How Can Other Countries Help China Reduce Air Pollution
J Thorac Dis. 2022 Jan; vii(1): 96–107.
What tin individuals do to reduce personal health risks from air pollution?
Received 2014 Jul 31; Accepted 2014 Nov twenty.
Abstract
In many areas of the world, concentrations of ambient air pollutants exceed levels associated with increased run a risk of astute and chronic health problems. While effective policies to reduce emissions at their sources are clearly preferable, some testify supports the effectiveness of individual actions to reduce exposure and health risks. Personal exposure to ambient air pollution can be reduced on high air pollution days by staying indoors, reducing outdoor air infiltration to indoors, cleaning indoor air with air filters, and limiting physical exertion, especially outdoors and nigh air pollution sources. Limited evidence suggests that the use of respirators may be effective in some circumstances. Awareness of air pollution levels is facilitated by a growing number of public air quality alert systems. Avoiding exposure to air pollutants is peculiarly of import for susceptible individuals with chronic cardiovascular or pulmonary illness, children, and the elderly. Research on mechanisms underlying the adverse health effects of air pollution have suggested potential pharmaceutical or chemopreventive interventions, such as antioxidant or antithrombotic agents, but in the absenteeism of data on health outcomes, no sound recommendations tin exist fabricated for master prevention. Health care providers and their patients should advisedly consider individual circumstances related to outdoor and indoor air pollutant exposure levels and susceptibility to those air pollutants when deciding on a course of activeness to reduce personal exposure and health risks from ambient air pollutants. Careful consideration is especially warranted when interventions may have unintended negative consequences, such as when efforts to avoid exposure to air pollutants atomic number 82 to reduced physical activity or when there is evidence that dietary supplements, such as antioxidants, accept potential agin health effects. These potential complications of partially effective personal interventions to reduce exposure or risk highlight the master importance of reducing emissions of air pollutants at their sources.
Keywords: Air pollution, prevention, cardiovascular disease, pulmonary disease, behavior
Introduction
Air pollution is a serious global public health problem that is managed well-nigh effectively past collective (societal) activeness to control emissions of both primary air pollutants and precursors that react to form secondary air pollutants. Unfortunately, in many areas of the world, concentrations of ambient air pollutants currently exceed levels believed to substantially increase risks of acute and chronic adverse human health effects. Affected areas include many of the urban communities where a majority of the world's population now lives and works (1). While waiting for governments to human activity, or controls to exist implemented, are there personal deportment that can be taken past individuals to effectively reduce the risks of adverse wellness furnishings from air pollution?
As reviewed elsewhere in this issue, scientific studies provide strong bear witness for a growing number of adverse health effects of exposure to air pollutants. Given the evidence of harm, the benefits of acting to reduce personal exposure to air pollution may seem self-evident. Indeed, studies have shown that reductions in exposure at the population level, either due to natural experiments or long-term trends, improve health outcomes (two,3). However, personal-level interventions may accept varying degrees of effectiveness for reducing exposure and/or reducing adventure, and at that place has been a dearth of research on actual health outcomes afterward personal interventions. This is due, at least in role, to difficulties in evaluating the effects of personal interventions on air pollution-attributable health events, which, despite their public wellness significance, have relatively low frequencies beyond broad populations. Also, personal actions to reduce exposure to air pollution are all-time viewed in the context of total take chances, considering such actions have the potential to crusade unintended health furnishings by altering other run a risk factors. Interventions aimed at reducing individual susceptibility, or increasing resilience, which may be complementary to deportment to reduce exposure, are promising but as even so unproven approaches to reducing take a chance.
Here, we review and evaluate various private-level strategies for reducing risk, based on the available evidence to date. The scope of this review is limited to ambient (outdoor-source) air pollution, including exposure to outdoor-source air pollution that occurs indoors, where many individuals spend the majority of their fourth dimension. The association of indoor and outdoor air pollution is governed by mass balance equations (4), which are modified by many of the interventions to reduce indoor exposure to air pollutants that are reviewed below. Our goal is not to systematically review culling approaches to reducing exposure and take a chance from outdoor-source air pollutants, only rather to provide a broad perspective on what we know and what we don't know near individual-level interventions to mitigate wellness risks from air pollution.
Reducing personal exposure to ambient air pollution
Staying indoors
Personal exposure to ambience air pollutants occurs in both indoor and outdoor environments, and the levels of exposure depend on the fractions of time an private spends in various indoor and outdoor environments, every bit well as the concentrations of outdoor-source air pollutants in those indoor and outdoor environments. In the developed world, people spend about xc% of their daily time indoors on boilerplate, with about lxx% of their daily time in residential homes (5). At that place is a lack of information on personal activeness patterns in the developing earth. Although ambient air pollutants such as particulate matter, ozone, and other gases infiltrate indoors from outdoors, concentrations are by and large lower indoors compared to outdoors, and spending time indoors by and large reduces exposure to ambient air pollutants. Indeed, environmental protection agencies in a number of countries propose members of the public to remain indoors every bit part of guidance to reduce exposure and thus acute health take chances on high air pollution days (6). All the same, it is worth noting that infiltration rates vary widely due to differences in building structures, indoor surface materials, air handling systems, building operating conditions, and ambient ecology conditions (due east.m., air current speed and direction, temperature, and air pollutant constituents). Concentrations of indoor air pollutants of ambient origin are primarily determined by the process of outdoor-to-indoor transport, which is a role of air exchange charge per unit (building ventilation). Closed windows, unremarkably associated with use of air conditioning in the developed world, tin can reduce air substitution rates by about 50% (vii), leading to reduced infiltration of ambient air pollutants to the indoor environment.
Personal exposure to ambience pollutants in the indoor environs is complicated by indoor air chemistry, through which some ambience pollutants are degraded (e.one thousand., Oiii and nitrate particles) and other new air pollutants are formed (due east.thou., aldehydes and ammonia) (8). Concentrations of ozone indoors accept been found to range widely from x% to 80% of outdoor concentrations, with ways of 40-50%, due to loss of ozone by chemical reactions that occur primarily on interior surfaces (ix). The effectiveness of staying indoors to reduce exposure to outdoor-source PM is more express due to typical penetration factors which can approach unity in the absence of air conditioning (ten), and relatively little loss of particles to surface degradation. Show that closing windows reduces penetration of PM and associated cardiovascular health adventure came from a recent written report of 300 good for you adults in Taipei who alternately opened and closed windows at dwelling for 2-week periods. Lin et al. [2013] institute associations between PM levels and agin changes in markers of cardiovascular disease risk (increased plasma CRP and fibrinogen, and decreased center rate variability) subsequently periods with windows open up, only no changes with windows closed (xi).
Recommendations to spend more fourth dimension indoors or make buildings "tighter" to reduce penetration of ambience pollutants are further complicated past variable indoor sources of air pollutants and the theoretical net risk from the different air pollutants that may be encountered indoors from both indoor and outdoor sources ( Figure 1 ). Staying indoors and decreasing habitation ventilation reduces personal exposures to pollutants of outdoor origin, but at the same time may potentially increase personal exposures and health risks from a variety of indoor-generated primary and secondary air pollutants, including volatile organic compounds from consumer products and building materials, and nitrogen oxides, carbon monoxide and particulate thing from indoor combustion activities such as cooking, wood burning, and smoking tobacco products. For example, Huang et al. [2014] reported that levels of indoor PM were associated with decreased eye rate variability (HRV) amid housewives. After adjustment for confounders, an interquartile range increase in PMii.5 was associated with statistically significant i.25-4.31% decreases in standard deviation of normal to normal (SDNN) and 0.12-3.71% decreases in root mean squared of successive differences (rMSSD) HRV, and these effects were stronger during stir-frying, cleaning with detergent, and burning incense (12).
Schematic diagram illustrating the complex processes that determine exposure to air pollutants of outdoor and indoor origin, including infiltration of outdoor-source pollutants, generation of indoor-source pollutants, chemical reactions in the air and on interior surfaces, adsorption and degradation on surfaces, and re-suspension and off-gassing from surfaces.
Cleaning indoor air
Portable or fundamental air cleaning systems can reduce concentrations of indoor air pollutants, of either outdoor or indoor origin. MacIntosh et al. [2008] conducted an indoor air quality report to characterize particle removal efficiencies of several types of central, in-duct air filters/cleaners (thirteen). The authors observed that indoor particles with diameters 0.iii-0.5 µm were effectively removed past either placing a v-inch pleated media filter (model BAYFTAH26M, Trane Residential Systems) or an electrostatic air cleaner in the ventilation duct. The application of the 5-inch pleated media filter reduced the indoor/outdoor (I/O) ratio of 0.iii-0.5 µm particles 0.eight to 0.two (75% decrease, 95% CI: 74-76%), and the electrostatic air cleaner reduced the I/O ratio from 0.8 to 0.05 (a 94% decrease, 95% CI: 93-95%) under typical indoor settings specified in Meng et al., [2009] (vii). Macintosh et al. [2008] further observed that PM2.5 can also be removed finer past ane-inch and v-inch pleated media filters (model BAYFTAH26M, Trane Residential Systems) in the ventilation duct (13). Under typical indoor settings, the 1-inch and 5-inch pleated media filters reduced I/O ratio of PM2.five from 0.forty to 0.27 (a 32.5% decrease, 95% CI: 29-36%) and from 0.twoscore to 0.08 (an 80% decrease, 95% CI: 79-81%), respectively (seven). Applied considerations that may limit the use of increased filtration include added energy costs, noise, and vesture and tear to the ventilation system.
Macintosh et al. [2010] modeled the health benefits of using a whole house in-duct air cleaner (14). The indoor-outdoor ratio of PMtwo.five will decrease from 0.57 with natural ventilation (passive air exchange through windows and other openings), to 0.35 with conventional in-duct filtration, to 0.1 with HEPA (loftier efficiency particle air) in-duct filtration. Based on modeling of the metropolitan areas of Cincinnati, Cleveland, and Columbus, Ohio, reduction in PMtwo.5 I/O ratio from 0.57 to 0.i subsequently adoption of in-duct HEPA filtration would lead to estimated almanac decreases of 700 (0.014%) premature deaths, 940 (0.019%) hospital and ER visit, and 130,000 (two.6%) asthma attacks
In improver to filtration in heating ventilation and air-conditioning (HVAC) systems, portable filter-based air cleaners have also been used to reduce indoor levels of PM2.5 and assess potential impacts of these reductions on acute health-related biomarkers in controlled experiments. Macintosh et al. [2008] reported that the PM2.5 can also be effectively removed with a single portable air cleaner with HEPA filter (13). Under typical conditions (vii), the operation of a single portable air cleaner with HEPA filter led to a decrease of I/O ratio from 0.4 to 0.14 (a 65% decrease, 95% CI: 63-67%). The actual removal rate is expected to be dependent upon the size of interior space, the ventilation rate, and the flow rate of the portable air cleaner. Bräuner et al. [2008] conducted a randomized double-blind, crossover study to quantify the affect of a portable HEPA filter-based indoor air intervention on microvascular function for healthy elderly individuals in Copenhagen (15). The HEPA filter intervention reduced both indoor PM2.5 mass concentrations (from 12.6 to 4.7 µg/m3) and particle number concentrations (from 10,016 to 3,206 particles/cm3), leading to an 8.1% (95% CI: 0.4-26.3% improvement in microvascular office. Another study in an area with prevalent woods smoke (Vancouver, BC area) used a similar HEPA filter intervention and reported like declines in indoor PM levels as well as improved microvascular part (16).
Reducing the constructive inhaled dose of air pollution
In addition to staying indoors, with or without further efforts to reduce indoor pollutant levels, reducing exertion tin can reduce the corporeality (dose) of air pollutants that are inhaled (17), and can modify the fraction of pollutant deposited or captivated in different regions of the respiratory tract. For example, an experimental study of healthy adults showed that total respiratory tract deposition of ultrafine particles (bore <100 nm) was nigh v-fold greater during moderate exercise than at remainder (18). Compared to the oral cavity, the nose is a more effective filter for preventing particles and h2o-soluble gases and vapors from reaching the lung (19). Thus, breathing through the oral cavity at college levels of exertion further increases the dose of pollutants that reach the lower respiratory. Another study showed that children six-10 years former had less nasal deposition of fine particles during light exercise compared to adults, suggesting that limiting exertion in children may be peculiarly important for reducing their exposure to PM (twenty).
Public wellness messages in dissimilar locales usually refer to avoiding vigorous, extended outdoor activity during air pollution episodes (21). Trade-offs between the health benefits of reduced inhalation exposure to air pollutants and the health benefits of physical activity per se need to be factored into individual recommendations and choices for reducing do at sure locations or times in order to mitigate health risks from reduce exposure to air pollution. Physical inactivity is a major run a risk factor for mortality and morbidity from cardiopulmonary and other diseases, and do has been shown to take powerful protective effects for a number chronic disease states (22). European risk assessments showed that, on average, the cardiovascular disease benefits of exercise outweigh the cardiovascular disease risks of increased exposure to air pollution associated with commuting by cycle alongside urban roadways (23,24). Reviewing bachelor studies that were mostly European, Hartog et al. found that, although boilerplate levels of exposure to particulate matter were college during auto driving than bicycle riding inside the same study, inhaled dose was estimated to be higher during cycling due to increased minute ventilation (23). They conducted a gamble assessment based on estimated street-level pollution levels in Amsterdam (in-vehicle and roadway PM2.five of about 35-40 µg/thou3), and institute that the cardiovascular benefits of replacing short automobile trips with cycling greatly outweighed the risk from increased exposure to outdoor air pollution. Similar assessments have not been washed to compare exercising indoors to exercising outdoors, or avoiding exercise both indoors and outdoors, either regularly or on high pollution days. Comprehensive evaluations would take into account differential individual chance and benefit profiles based on susceptibility to adverse furnishings of air pollution, relative benefits from exercise, dose of air pollution, intensity of do, and other factors.
Fugitive outdoor activity when and where air pollutant levels are higher
Ambient air pollution levels vary seasonally, day-to-24-hour interval, and by time-of-day. For example, ultraviolet light from the sun activates the chemical reactions that form ozone, generally leading to college concentrations in late morning time through early evening (25). Alternatively, ozone concentrations may tiptop later in the evening or at night in locations that are downwind of ozone germination (25). Levels of air pollutants also vary in dissimilar microenvironments, such as outdoors in variable proximity to sources, at home, at workplaces, in schools, in vehicles, etc. Individuals can know when air pollution levels are likely to be elevated either by sensing poor air quality (odour, irritation, symptoms), having noesis of conditions that tend to lead to college air pollutant levels in their area, or via public communications based on measured or predicted levels at air monitoring stations. In club to virtually finer adjust behavior to reduce exposure and risk, individuals must be able to anticipate when and where air pollutant levels are likely to be elevated to a higher place levels thought to confer increased take chances.
Ambient air pollutant concentrations are measured by air pollution monitoring networks in a number of countries around the earth. These measurements are combined with mathematical models to forecast air pollutant levels over 24 to 48 hours. Both measured concentrations and predicted levels are disseminated to the public in various ways. At present, at that place is no accepted consensus standardization of approaches or methods, but in general, well-nigh government convert increasing concentrations of major air pollutants (ozone, PM2.5, PM10, carbon monoxide, nitrogen dioxide, and sulfur dioxide) into severity bands labeled with progressive degrees of risk. For instance, the US EPA's Air Quality Alphabetize (AQI) includes band ratings of 'good, moderate, unhealthy for sensitive individuals, unhealthy, very unhealthy, and hazardous'. The Mutual Air Quality Index (CAQI), used on the European Marriage'due south Air Quality Now website, labels band ratings equally 'very low, low, medium, high, and very high'. The AQI, CAQI and other systems use unlike air pollutant cut-off values to define bands. Therefore, the severity bands are non straight comparable from land to country, fifty-fifty though the severity terms may be the same, because ratings are generally based on how a pollutant concentration compares to national or other regulatory pollutant thresholds that vary from land to land. All of these indices simplify complex air quality information into relatively straightforward communications to the public, at the expense, to some degree, of precision and accurateness. For example, most consider each air pollutant separately, and many report a single alphabetize value based on the pollutant with the highest alphabetize value, ignoring poorly-understood, but likely important, interactive furnishings between different pollutants. The values of nigh daily indices correspond to standards for daily (24-hour) or shorter averaging times, however, long-term (almanac) boilerplate standards for the pollutant may be exceeded fifty-fifty if the shorter-term standards are exceeded merely infrequently. Aggregate indices that consider the conjoint effects of a number of monitored air pollutants, over diverse averaging times, have been proposed but accept not been incorporated into (26,27).
It is generally assumed that levels of air pollutants that trigger air quality alerts are below thresholds of homo detection by odor, irritation, or specific symptomatic responses. However, levels or air pollutants at key monitors tin misrepresent local atmospheric condition, especially during transient, local air pollution episodes that humans may sense by odor, irritation, or other responses (28). Some studies have found correlations between perceptions of air quality and monitoring data (29-32), merely other studies have not (33,34).
The extent to which individuals in dissimilar communities are aware of air quality indices or alerts has varied greatly in surveys and focus groups conducted in the US, Canada, and UK (28). There is niggling data on the extent to which individuals change behavior to reduce exposure either in response to air quality data or perceptions of exposure. In a study of Portland and Houston in the United states in 2005-2006, a 3rd of 1,962 participants were enlightened of air quality alerts, just only 10-15% of individuals reported changing behavior in response to predicted poor air quality, and cited perceptions of poor air quality as driving their beliefs, non official advisories (34). Similarly, in a cross-sectional study of 33,888 developed participants, in six states, in the 2005 Behavioral Take chances Factor Surveillance Arrangement (BRFSS), about a 3rd of adults with asthma and xvi% without asthma reported change in outdoor activity due to media alerts (35). Private perception of poor air quality and health professional communication greatly increased the prevalence of reported behavior change. Nosotros could discover no studies that accept assessed associations between wellness outcomes and exposure to public health advisories, physician recommendations, or bodily personal behavior change to reduce exposure to air pollutants.
Reducing exposure in microenvironments near sources such as traffic
Air pollutant levels in specific microenvironments are highly variable, and directly measurements or estimates of these levels are rarely available to aid individuals in making decisions nearly reducing exposure, simply some generalizations about expected relative levels of air pollutants under different types of atmospheric condition in detail types of microenvironments can be useful. For example, traffic-related air pollution, may present increased risk of adverse health effects to broad populations in many urban areas of the world. Traffic-related pollutants consist of particles and gases emitted from internal combustion engines, their reaction products, tire and vehicle wear, and resuspended road grit. Concentrations of these pollutants turn down in steep gradients with distance from roadways, but large urban populations living and/or working in proximity to roadways, likewise equally commuters on roadways, are among those virtually likely to be exposed (36). Traffic-related air pollutants accept get relatively more important in areas of the world where increased industrial air pollution controls take reduced the contribution of stationary sources to total air pollution emissions. Although per-vehicle emissions have been drastically reduced in many parts of the globe, and a recent decline in total vehicle miles travelled (VMT) in the adult world, at that place has been a rapid increase in motor vehicle buying and VMT travelled in developing countries (37).
Individuals can reduce exposure to air pollutants and potential adverse health effects by avoiding regular physical activeness alongside loftier-traffic roadways or near other sources of combustion such as called-for of wood, biomass, or other materials. Exposure to traffic pollutants can exist a rational consideration in choosing walking, biking, or exercise routes. In general, traffic pollution concentrations fall rapidly at distances from roadways, budgeted background within about 500 meters, bold no other local sources are nearby (36). Various web-based applications can assist individuals in finding culling routes (e.chiliad., http://www.cyclevancouver.ubc.ca/cv.aspx in Vancouver, Canada).
Individuals who commute to work in personal vehicles or public transportation receive a substantial portion of their daily dose of air pollution during commuting activities (38,39). Pollutants emitted past nearby vehicles are the main source of on-roadway exposure. About air intake filters in passenger vehicles are relatively low efficiency and air pollutants enter through open up windows, leaks in door and window seals, and other openings. Vehicle operating conditions take been shown to strongly influence concentrations of air pollutants in vehicles, with I/O ratios ranging from close to one.0 with windows open up to 0.2 or less with windows closed and ventilation set to recirculate cabin air. Vehicle speed and age also strongly affecting I/O ratios (40). Reductions in I/O ratio are generally greater in vehicles with cabin recirculation filters that are condign more common in later model passenger vehicles. Reductions of in-cabin PM exposure of up to 40% with cabin filters accept been observed (41). Amid a panel of 60 healthy adults commuting ii hours by car in Taipei, Chuang et al. [2013] found that associations between in –vehicle PMii.5 and astute decreases in HRV were modified by keeping the ventilation arrangement in recirculation fashion with the air conditioner on (42). An interquartile range increase in PM2.5 was associated with a iv.8% (95% CI: 2.9-6.vii%) decrease in SDNN and half dozen.nine% (95% CI: 5.ix-seven.9%) decrease in RMSSD with air conditioner off, compared to 0.seven% (95% CI: 0.3-1.1%) decrease in SDNN and 0.i (95% CI: −one.4-1.6) decrease in RMSSD with air conditioner on, with P value for the interaction in both comparisons <0.01.
Personal protective equipment—respirators
In some urban areas around the world, it is not unusual to observe individuals wearing various types of respirators on urban streets in gild to reduce exposure to air pollutants. The ability of a respirator to remove contaminants from inhaled air depends on the contaminant, blazon of filter or adsorbent textile, respirator type and weather of use. Although, relatively inexpensive respirators with filter material for particulate thing are widely available, no single absorptive, or available combination of adsorbents, tin can efficiently remove the various gas phase air pollutants that may exist encountered. Gaseous pollutants can be removed based on their physicochemical properties, such equally reactivity, molecular weight, and volatility. Therefore, the removal mechanism for different gaseous pollutant can be quite unlike, i.e., chemical reaction vs. adsorption; and a detail adsorbent is only suitable for removal ane or a groups of pollutants with similar physicochemical backdrop. In full general, assuming that the filter or adsorbent material is appropriate for the type of air pollutant, the efficiency of air pollutant removal by tight-plumbing fixtures negative pressure respirators depends largely on the quality of the individual'south face seal. With a proper seal, the National Institutes for Occupational Safety and Health (NIOSH), which certifies respirators in the United states, assigns a "protection factor" of ten to the filtering-facepiece respirators (commonly referred to as a facemask) (43). This ways that when properly worn by an individual who has been fit-tested, these respirators are expected to reduce the concentration of the air contaminant within the facepiece to ≤10% of the concentration exterior the facepiece. Fit testing and instruction in proper selection and employ of respirators is a function of standards and practices for industrial respiratory protection in many countries, just may be unavailable, and peradventure impractical, when respirators are used by large populations in non-industrial settings.
Limited evidence suggests that the use of negative pressure air-purifying respirators under experimental conditions may reduce cardiovascular risks from exposure to urban PM. Langrish et al. [2009] and Langrish et al. [2012] conducted controlled intervention studies with healthy individuals and patients with coronary centre disease, who walked along an assigned route in the middle of Beijing for two hours with and without a negative pressure air-purifying respirator (44,45). Among 15 healthy subjects, the authors reported that wearing the facemask was associated with decreased systolic claret pressure during the walk compared to not wearing the facemask (121 mmHg without mask vs. 114 mmHg with mask, P<0.01), and increased heart rate variability (SDNN 61.two ms without mask vs. 65.6 ms with facemask, P<0.05) over 24 hours, both indicators of decreased cardiovascular chance (44). Among 98 patients with heart disease, similar effects were observed, with the addition of reduced ST-segment low (−142 vs. −156 µV, P=0.046) over 24 hours comparing walks with the facemask to walks without the facemask (45). This is encouraging, because presumably beneficial cardiovascular effects were nonetheless observed despite the added work of breathing imposed on the wearer by this type of negative-pressure, air-purifying respirator.
However, wearing this type of respirator has physiological furnishings that may confound cardiovascular effects that might be attributed to reductions in exposure to PM. For example, a study of salubrious men wearing negative-pressure, air-purifying respirators while exercising at various levels on a treadmill constitute monotonic increases in center rate progressing from rest to increasing levels of practise, but systolic BP showed a biphasic response, being significantly lower at rest and higher at high levels of exercise (46). Thus, net benefit of wearing a respirator, specially in a susceptible private for whom increased work of breathing is important, may be a circuitous function that does non translate simply from the actual reduction in particle exposure. Any net benefits of the practice of wearing respirators to reduce adventure from ambient particulate thing air pollution will depend on the exposure reduction efficiency of the respirator and the concentration and potency of the particulate thing mixture, as well as any detrimental physiological and/or psychological furnishings of respiratory utilise. Results from single studies, like the Langrish et al. studies in Beijing, are not easily generalizable to other locales, populations, and circumstances (44,45). Additional studies are needed to replicate these findings and to clarify conditions of use that will optimize outcomes in unlike groups.
Regardless of the level of effectiveness at reducing exposure to air pollutants, the use of personal respiratory protection may be limited by individual and public acceptability, based on comfort, appearance, and inhibition of communication and other activities. Many notice respirator contact with the face, perceived increased piece of work-of-breathing and thermal discomfort intolerable for more than brusque periods of time. One study institute that air temperatures at the face averaged 7.v deg C higher during use of respirator at rest and during exercise (46). Some individuals may experience feet similar to claustrophobia when wearing a respirator, and facial features and facial hair may make information technology impossible to accomplish an acceptably tight fit (43).
Knowing if one is more or less likely to be susceptible
In addition to knowing when and where exposures are, or are likely to be, more intense, individuals can better optimize the balance of personal risks and benefits by knowing if they are more likely than the full general population to be particularly sensitive to harmful furnishings of different air pollutants. While children and young adults may be highly susceptible to some of the subclinical changes caused by air pollution (47,48), clinical events attributable to air pollution, such as myocardial infarction, stroke, or hospitalization for respiratory failure or center failure, will of course be much more common in older individuals with advanced underlying disease such every bit COPD or atherosclerotic plaques. Individuals vary in sensitivity to agin effects of air pollutants, and more-sensitive individuals are probable to obtain more benefit from efforts to reduce personal exposure (49). Generally, individuals with chronic cardiovascular or respiratory affliction, children, fetuses, and the elderly are thought to be most sensitive to the major "criteria" air pollutants. Adverse effects can be distinguished as either chronic disease due to cumulative exposure over time, or astute effects of short-term exposure. For acute effects, individuals with asthma, COPD, diabetes, and underlying atherosclerotic cardiovascular disease are regarded as among the nearly vulnerable, due to demonstrated risk of exacerbation of these or related weather condition with short-term exposure to elevated levels of air pollution (50,51). Emerging evidence suggests that the developing fetus may be particularly sensitive to maternal exposure to air pollutants (48,52). In full general, children and the elderly are idea to be more than susceptible to air pollution effects; children due to increased body-size-adjusted dose, young detoxifying mechanisms, and developing organ system and the elderly due to increased prevalence of chronic affliction or other factors contributing to age-related loss of resilience and increased take chances (53). There is some evidence that genetic variants such as polymorphisms in antioxidant genes may confer increased run a risk from air pollutants [see reviews (54,55) and Chen et al. in this effect (56)]. Genetic, as well every bit epigenetic, variation holds promise for time to come tailoring of interventions based on private susceptibility, only at present there are no clinically applicable tests for varying levels of individual sensitivity to the chronic or astute wellness effects of air pollutants.
Interventions to modify individual susceptibility
Chronic medical weather, such as asthma, COPD, and traditional cardiovascular disease run a risk factors may make individuals more susceptible to the agin health effects of air pollution. Effective medical treatment and management of these conditions seems to be a logical first step for ameliorating increased run a risk from ambient or indoor pollutants although no epidemiological or clinical studies have provided direct bear witness that such treatment modifies the adverse effects of air pollution. Consensus standards for managing asthma, COPD, and middle disease do include limiting exposure to ambient air pollution amid guidelines for preventing exacerbation of these conditions (49,57,58). However, there is currently no straight show that improved clinical management reduces take chances of adverse health furnishings from exposure to air pollution.
We know from cohort studies (Women'south Health Initiative, Vi Cities) that chronic exposure to higher (non necessarily loftier in global terms) levels of air pollutants are indisputably associated with development of COPD and atherosclerotic CVD, including bloodshed (59-61). From panel studies nosotros know that mean solar day to 24-hour interval, and even hour to hour changes in particulate pollution levels substantially increase risk for MI, heart failure, and stroke. From other panel studies, we have learned a corking deal about the pathophysiology of these clinical outcomes (47,62-64). These studies have confirmed the important, and to some extent reversible roles for pathophysiologic processes such as oxidative stress, pulmonary and systemic inflammation, vascular/endothelial dysfunction, and increased signs of coagulation, as central processes that wax and wane acutely with air pollution and probable trigger astute events and contribute to evolution of chronic illness such every bit ASCVD. Critically, these aforementioned processes are also invoked in the pathophysiology of middle and lung affliction, independent of air pollution. The overlap is remarkable just not surprising because the disease endpoints are the same. Thus, nosotros must ask what we tin can learn from preventive pulmonary and cardiology methods that are applicable to the special case of air pollution'southward effects on centre and lung affliction.
Unfortunately, the cupboard is rather bare in terms of proven interventions for the general cardiologic example that tin can then be applied to the more specific case of air pollution, where no such experiments have been tried. The Mediterranean diet has been shown to both decrease total and cardiovascular bloodshed and to exist associated with improved biomarkers of cardiovascular risk (65). However, multiple randomized controlled tests of antioxidant and vitamin supplements, based on the confirmed high levels of antioxidants in the Mediterranean and other beneficial diets, and confirmed activity in in vitro and in vivo laboratory tests, have not shown benefit and in some randomized trials have proven harmful (66). Thus antioxidant supplementation cannot be confidently recommended to counteract air pollution. Indirect antioxidants such as sulforaphane (in broccoli sprouts) take shown promising astute pilot effects but are not regarded as proven for populations (67). Statins are antioxidant every bit well equally lipid-lowering, but these are over again unproven in a population without a primary lipid-lowering indication (68,69).
Fish oil supplementation has shown beneficial effects not simply on blood lipids only also on eye rate variability (68,69). Beets, and other foods rich in nitrates, exercise demonstrate a beneficial effect on blood pressure (70) but there is no outcomes-based evidence that supplementation of dietary nitrates, or pharmacologic control of blood pressure, is protective against cardiopulmonary effects of air pollution.
Aspirin is widely recommended and effective for reducing MI and stoke gamble after a primary event and given the data showing over a doubling of MI run a risk and increased platelet activation with acute exposure to ambient PM, this is an attractive intervention (47,71). However, calculation of adventure-benefit and duration of therapy and actual modify in wellness outcomes or biomarkers associated with air pollution are lacking at this time. Thus, despite compelling mechanistic show, no specific recommendations for dietary changes or chemoprevention can exist made beyond those already fabricated for prevention of eye and lung disease in general.
Conclusions
Limited evidence supports individual deportment to reduce cardiopulmonary health risks from personal exposure to ambient air pollutants by staying indoors and limiting physical exertion when air pollutant levels exceed health-based thresholds. Improved management of chronic diseases that are affected by air pollution will subtract overall risk of agin outcomes. Available evidence is less clear virtually the benefits of efforts to reduce susceptibility to air pollution by pharmaceutical or chemopreventive approaches. It is clear that the relative contribution of indoor- and outdoor-generated pollutants to personal exposures depends on multiple factors, including the type of pollutants, building structure, indoor sources, and personal activities (vii). Health care providers and their patients should consider these factors and tailor interventions to individual circumstances in guild to maximize the net exposure reduction based on private circumstances (53). While it may not exist applied to explicitly and reliably quantify these exposures, if indoor pollutant generation can exist minimized, then staying indoors makes more than sense. In addition to the residuum of air pollutant exposures, benefits of whatever reduction in exposure to air pollutants must be weighed against the physical and mental wellness benefits of outdoor action. In addition to reducing outdoor activeness on high pollution days, these public health letters may discourage outdoor action at other times. The benefits of physical activity may be peculiarly bully for individuals who are as well more sensitive to air pollution, such equally those with heart and respiratory affliction. On the other mitt, the residuum will tip more than towards limiting activity every bit air pollution concentrations reach higher levels, on days with particularly poor air quality, or in areas with chronically elevated levels of air pollution. Encouraging individuals to do at locations and times when air pollutant levels are lower may assist to preserve the benefits of practice, while minimizing the wellness risks from exposure to air pollution. To our knowledge, no explicit formulae for calculating and optimizing this risk-benefit ratio are available at this fourth dimension.
Acknowledgements
Funding: This work was supported by NIH grant ES005022.
Disclosure: The authors declare no disharmonize of interest.
References
1. United nations, Department of Economic and Social Affairs, Population Partition (2014). World Urbanization Prospects: The 2014 Revision, Highlights (ST/ESA/SER.A/352).
two. Pope CA, third, Ezzati Chiliad, Dockery DW. Fine-particulate air pollution and life expectancy in the United States. N Engl J Med 2009;360:376-86. [PMC complimentary article] [PubMed] [Google Scholar]
3. Laden F, Schwartz J, Speizer Iron, et al. Reduction in fine particulate air pollution and mortality: Extended follow-upwards of the Harvard 6 Cities study. Am J Respir Crit Care Med 2006;173:667-72. [PMC free article] [PubMed] [Google Scholar]
4. Nazaroff WW. Indoor particle dynamics. Indoor Air 2004;14 Suppl seven:175-83. [PubMed] [Google Scholar]
5. Klepeis NE, Nelson WC, Ott WR, et al. The National Homo Activity Design Survey (NHAPS): a resource for assessing exposure to ecology pollutants. J Expo Anal Environ Epidemiol 2001;11:231-52. [PubMed] [Google Scholar]
half-dozen. Plaia A, Ruggieri M: Air quality indices: a review. Rev Environ Sci Bio 2011;10:165-79. [Google Scholar]
vii. Meng QY, Spector D, Colome South, et al. Determinants of Indoor and Personal Exposure to PM(2.5) of Indoor and Outdoor Origin during the RIOPA Study. Atmos Environ (1994) 2009;43:5750-8. [PMC gratuitous article] [PubMed] [Google Scholar]
8. Weschler CJ. Ozone in indoor environments: concentration and chemistry. Indoor Air 2000;10:269-88. [PubMed] [Google Scholar]
nine. Weschler CJ. Ozone's impact on public health: contributions from indoor exposures to ozone and products of ozone-initiated chemical science. Environ Health Perspect 2006;114:1489-96. [PMC free article] [PubMed] [Google Scholar]
10. Thatcher TL, Layton DW. Deposition, Resuspension, and Penetration of Particles within a Residence. Atomspheric Surround 1995;29:1487-97. [Google Scholar]
xi. Lin LY, Chuang HC, Liu IJ, et al. Reducing indoor air pollution past air conditioning is associated with improvements in cardiovascular health amid the general population. Sci Total Environ 2013;463-464:176-81. [PubMed] [Google Scholar]
12. Huang YL, Chen HW, Han BC, et al. Personal exposure to household particulate thing, household activities and centre rate variability amongst housewives. PLoS I 2014;nine:e89969. [PMC costless article] [PubMed] [Google Scholar]
13. Macintosh DL, Myatt TA, Ludwig JF, et al. Whole house particle removal and clean air delivery rates for in-duct and portable ventilation systems. J Air Waste Manag Assoc 2008;58:1474-82. [PubMed] [Google Scholar]
14. Macintosh DL, Minegishi T, Kaufman Yard, et al. The benefits of whole-house in-duct air cleaning in reducing exposures to fine particulate matter of outdoor origin: a modeling analysis. J Expo Sci Environ Epidemiol 2010;20:213-24. [PubMed] [Google Scholar]
fifteen. Bräuner EV, Forchhammer Fifty, Møller P, et al. Indoor particles affect vascular function in the aged: an air filtration-based intervention study. Am J Respir Crit Care Med 2008;177:419-25. [PubMed] [Google Scholar]
16. Allen RW, Carlsten C, Karlen B, et al. An air filter intervention study of endothelial function amid healthy adults in a woodsmoke-impacted customs. Am J Respir Crit Care Med 2011;183:1222-xxx. [PubMed] [Google Scholar]
17. Panis LI. Cycling: health benefits and risks. Environ Wellness Perspect 2011;119:a114; author reply a114-a114; author reply a115. [PMC gratis article] [PubMed]
18. Daigle CC, Chalupa DC, Gibb FR, et al. Ultrafine particle degradation in humans during rest and exercise. Inhal Toxicol 2003;xv:539-52. [PubMed] [Google Scholar]
xix. Heyder J, Gebhart J, Rudolf G, et al. Deposition of particles in the human respiratory tract in the size range 0.005–15 µm. J Aerosol Sci 1986;17:811-25. [Google Scholar]
20. Bennett WD, Zeman KL, Jarabek AM. Nasal contribution to breathing and fine particle deposition in children versus adults. J Toxicol Environ Health A 2008;71:227-37. [PubMed] [Google Scholar]
21. Campbell ME, Li Q, Gingrich SE, et al. Should people exist physically active outdoors on smog alert days? Can J Public Health 2005;96:24-eight. [PMC costless article] [PubMed] [Google Scholar]
22. Warburton DE, Nicol CW, Bredin SS. Health benefits of physical activity: the testify. CMAJ 2006;174:801-9. [PMC gratuitous article] [PubMed] [Google Scholar]
23. Hartog JJ, Boogaard H, Nijland H, et al. Do the health benefits of cycling outweigh the risks? Cien Saude Colet 2011;sixteen:4731-44. [PubMed] [Google Scholar]
24. Rojas-Rueda D, de Nazelle A, Teixidó O, et al. Replacing car trips past increasing bike and public send in the greater Barcelona metropolitan surface area: a health impact assessment study. Environ Int 2012;49:100-9. [PubMed] [Google Scholar]
26. Ruggieri Grand, Plaia A.An aggregate AQI: Comparing different standardizations and introducing a variability alphabetize. Sci Total Environ 2012;420:263-72. [PubMed] [Google Scholar]
27. Kyrkilis 1000, Chaloulakou A, Kassomenos PA. Development of an aggregate Air Quality Index for an urban Mediterranean agglomeration: relation to potential health effects. Environ Int 2007;33:670-vi. [PubMed] [Google Scholar]
28. Johnson BB. Experience with urban air pollution in Paterson, New Bailiwick of jersey and implications for air pollution advice. Risk Anal 2012;32:39-53. [PubMed] [Google Scholar]
29. Cole DC, Pengelly LD, Eyles J, et al. Consulting the customs for environmental health indicator development: the case of air quality. Health Promot Int 1999;14:145-54. [Google Scholar]
thirty. Day R.Place and the feel of air quality. Health Place 2007;13:249-sixty. [PubMed] [Google Scholar]
31. Bonnes Thousand, Uzzell D, Carrus G, et al. Inhabitants' and Experts' Assessments of Environmental Quality for Urban Sustainability. J Soc Bug 2007;63:59-78. [Google Scholar]
32. Hunter PR, Bickerstaff K, Davies MA. Potential sources of bias in the apply of individual's recall of the frequency of exposure to air pollution for use in exposure assessment in epidemiological studies: a cross-exclusive survey. Environ Wellness 2004;3:3. [PMC free article] [PubMed] [Google Scholar]
33. Zeidner G, Shechter Thousand.Psychological responses to air pollution: Some personality and demographic correlates. J Environ Psychol 1988;viii:191-208. [Google Scholar]
34. Semenza JC, Wilson DJ, Parra J, et al. Public perception and beliefs alter in relationship to hot conditions and air pollution. Environ Res 2008;107:401-11. [PubMed] [Google Scholar]
35. Wen XJ, Balluz 50, Mokdad A. Association between media alerts of air quality index and change of outdoor activity amongst adult asthma in half-dozen states, BRFSS, 2005. J Community Health 2009;34:40-6. [PubMed] [Google Scholar]
36. HEI Panel on the Wellness Furnishings of Traffic-Related Air Pollution. 2010. Traffic-Related Air Pollution: A Critical Review of the Literature on Emissions, Exposure, and Wellness Effects. HEI Special Written report 17. Wellness Effects Institute, Boston, MA. [Google Scholar]
38. de Nazelle A, Nieuwenhuijsen MJ, Antó JM, et al. Improving wellness through policies that promote active travel: a review of show to support integrated wellness touch on assessment. Environ Int 2011;37:766-77. [PubMed] [Google Scholar]
39. Zuurbier G, Hoek M, Oldenwening Grand, et al. Commuters' exposure to particulate matter air pollution is afflicted by mode of transport, fuel type, and road. Environ Wellness Perspect 2010;118:783-9. [PMC complimentary article] [PubMed] [Google Scholar]
40. Hudda N, Kostenidou E, Sioutas C, et al. Vehicle and driving characteristics that influence in-cabin particle number concentrations. Environ Sci Technol 2011;45:8691-7. [PubMed] [Google Scholar]
41. Xu B, Zhu Y.Investigation on lowering commuters' in-cabin exposure to ultrafine particles. Transp Res Part D: Transport Environ 2013;18:122-30. [Google Scholar]
42. Chuang HC, Lin LY, Hsu YW, et al. In-car particles and cardiovascular health: an air-conditioning-based intervention report. Sci Total Environ 2013;452-453:309-thirteen. [PubMed] [Google Scholar]
43. Bollinger N. eds. NIOSH Respirator Option Logic. Cincinnati: Createspace, 2004. [Google Scholar]
44. Langrish JP, Mills NL, Chan JK, et al. Beneficial cardiovascular effects of reducing exposure to particulate air pollution with a uncomplicated facemask. Part Fibre Toxicol 2009;six:8. [PMC free article] [PubMed] [Google Scholar]
45. Langrish JP, Li Ten, Wang S, et al. Reducing personal exposure to particulate air pollution improves cardiovascular health in patients with coronary eye disease. Environ Health Perspect 2012;120:367-72. [PMC free commodity] [PubMed] [Google Scholar]
46. Jones JG. The physiological cost of wearing a disposable respirator. Am Ind Hyg Assoc J 1991;52:219-25. [PubMed] [Google Scholar]
47. Rich DQ, Kipen HM, Huang W, et al. Association betwixt changes in air pollution levels during the Beijing Olympics and biomarkers of inflammation and thrombosis in healthy young adults. JAMA 2012;307:2068-78. [PMC costless article] [PubMed] [Google Scholar]
48. Wright RJ, Brunst KJ. Programming of respiratory health in childhood: influence of outdoor air pollution. Curr Opin Pediatr 2013;25:232-9. [PubMed] [Google Scholar]
49. Brook RD, Rajagopalan S, Pope CA, 3rd, et al. Particulate thing air pollution and cardiovascular disease: An update to the scientific statement from the American Heart Clan. Apportionment 2010;121:2331-78. [PubMed] [Google Scholar]
l. Janghorbani M, Momeni F, Mansourian M.Systematic review and metaanalysis of air pollution exposure and risk of diabetes. Eur J Epidemiol 2014;29:231-42. [PubMed] [Google Scholar]
51. Hussain S, Laumbach R, Coleman J, et al. Controlled exposure to diesel exhaust causes increased nitrite in exhaled breath condensate amidst subjects with asthma. J Occup Environ Med 2012;54:1186-91. [PMC gratuitous article] [PubMed] [Google Scholar]
52. Backes CH, Nelin T, Gorr MW, et al. Early life exposure to air pollution: how bad is it? Toxicol Lett 2013;216:47-53. [PMC free article] [PubMed] [Google Scholar]
54. Peden DB. The epidemiology and genetics of asthma risk associated with air pollution. J Allergy Clin Immunol 2005;115:213-9; quiz 220. [PubMed] [Google Scholar]
55. Bell ML, Zanobetti A, Dominici F. Show on vulnerability and susceptibility to health risks associated with short-term exposure to particulate matter: a systematic review and meta-analysis. Am J Epidemiol 2013;178:865-76. [PMC gratuitous article] [PubMed] [Google Scholar]
56. Chen Z, Salam MT, Eckel SP, et al. Chronic effects of air pollution on respiratory health in Southern California children: findings from the Southern California Children's Wellness Study. J Thorac Dis 2014. [Epub ahead of print]. [PMC free article] [PubMed] [Google Scholar]
57. Global Strategy for the Diagnosis, Management and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Affliction (Golden) 2014. Available online: http://www.goldcopd.org/ [PMC free article] [PubMed]
59. Miller KA, Siscovick DS, Sheppard L, et al. Long-term exposure to air pollution and incidence of cardiovascular events in women. N Engl J Med 2007;356:447-58. [PubMed] [Google Scholar]
60. Dockery DW, Pope CA, 3rd, Xu X, et al. An clan between air pollution and bloodshed in six U.S. cities. North Engl J Med 1993;329:1753-ix. [PubMed] [Google Scholar]
61. Andersen ZJ, Hvidberg M, Jensen SS, et al. Chronic obstructive pulmonary disease and long-term exposure to traffic-related air pollution: a cohort study. Am J Respir Crit Care Med 2011;183:455-61. [PubMed] [Google Scholar]
62. Rückerl R, Hampel R, Breitner South, et al. Associations between ambient air pollution and claret markers of inflammation and coagulation/fibrinolysis in susceptible populations. Environ Int 2014;lxx:32-49. [PubMed] [Google Scholar]
63. Huang W, Wang One thousand, Lu SE, et al. Inflammatory and oxidative stress responses of salubrious young adults to changes in air quality during the Beijing Olympics. Am J Respir Crit Care Med 2012;186:1150-ix. [PMC free commodity] [PubMed] [Google Scholar]
64. Laumbach RJ, Rich DQ, Gandhi Due south, et al. Acute changes in centre rate variability in subjects with diabetes following a highway traffic exposure. J Occup Environ Med 2010;52:324-31. [PMC costless article] [PubMed] [Google Scholar]
65. Martinez-Gonzalez MA, Bes-Rastrollo 1000, Serra-Majem Fifty, et al. Mediterranean nutrient pattern and the primary prevention of chronic disease: recent developments. Nutr Rev 2009;67 Suppl one:S111-6. [PubMed] [Google Scholar]
66. Fortmann SP, Burda BU, Senger CA, et al. Vitamin and mineral supplements in the principal prevention of cardiovascular disease and cancer: An updated systematic show review for the U.S. Preventive Services Chore Force. Ann Intern Med 2013;159:824-34. [PubMed] [Google Scholar]
67. Egner PA, Chen JG, Zarth AT, et al. Rapid and sustainable detoxication of airborne pollutants by broccoli sprout beverage: results of a randomized clinical trial in Communist china. Cancer Prev Res (Phila) 2014;seven:813-23. [PMC free commodity] [PubMed] [Google Scholar]
68. Schwab U, Lauritzen L, Tholstrup T, et al. Result of the amount and type of dietary fat on cardiometabolic risk factors and take a chance of developing type 2 diabetes, cardiovascular diseases, and cancer: a systematic review. Food Nutr Res 2014;58. [PMC free article] [PubMed] [Google Scholar]
69. Billman GE. The furnishings of omega-3 polyunsaturated fatty acids on cardiac rhythm: a critical reassessment. Pharmacol Ther 2013;140:53-lxxx. [PubMed] [Google Scholar]
70. Siervo M, Lara J, Ogbonmwan I, et al. Inorganic nitrate and beetroot juice supplementation reduces claret force per unit area in adults: a systematic review and meta-analysis. J Nutr 2013;143:818-26. [PubMed] [Google Scholar]
71. Peters A, Dockery DW, Muller JE, et al. Increased particulate air pollution and the triggering of myocardial infarction. Circulation 2001;103:2810-5. [PubMed] [Google Scholar]
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4311076/
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