The health effects of traffic-related air pollution (TRAP) continue to be of important public health interest. Following its well-cited 2010 critical review, the Health Effects Institute (HEI) ...appointed a new expert Panel to systematically evaluate the epidemiological evidence regarding the associations between long-term exposure to TRAP and selected adverse health outcomes. Health outcomes were selected based on evidence of causality for general air pollution (broader than TRAP) cited in authoritative reviews, relevance for public health and policy, and resources available.
The Panel used a systematic approach to search the literature, select studies for inclusion in the review, assess study quality, summarize results, and reach conclusions about the confidence in the evidence. An extensive search was conducted of literature published between January 1980 and July 2019 on selected health outcomes. A new exposure framework was developed to determine whether a study was sufficiently specific to TRAP.
In total, 353 studies were included in the review. Respiratory effects in children (118 studies) and birth outcomes (86 studies) were the most commonly studied outcomes. Fewer studies investigated cardiometabolic effects (57 studies), respiratory effects in adults (50 studies), and mortality (48 studies).
The findings from the systematic review, meta-analyses, and evaluation of the quality of the studies and potential biases provided an overall high or moderate-to-high level of confidence in an association between long-term exposure to TRAP and the adverse health outcomes all-cause, circulatory, ischemic heart disease and lung cancer mortality, asthma onsetin chilldren and adults, and acute lower respiratory infections in children. The evidence was considered moderate, low or very low for the other selected outcomes.
In light of the large number of people exposed to TRAP – both in and beyond the near-road environment - the Panel concluded that the overall high or moderate-to-high confidence in the evidence for an association between long-term exposure to TRAP and several adverse health outcomes indicates that exposures to TRAP remain an important public health concern and deserve greater attention from the public and from policymakers.
•A systematic review was conducted on associations between long-term exposure to traffic-related air pollution and non-accidental mortality.•A new exposure framework was developed to determine ...whether a study was sufficiently specific to TRAP, which includes studies beyond the near-roadway environment.•The overall confidence in the evidence for a positive association between long-term exposure to TRAP and non-accidental mortality was high.
The health effects of traffic-related air pollution (TRAP) continue to be of important public health interest across the globe. Following its 2010 review, the Health Effects Institute appointed a new expert Panel to systematically evaluate the epidemiological evidence regarding the associations between long-term exposure to TRAP and selected health outcomes. This paper describes the main findings of the systematic review on non-accidental mortality.
The Panel used a systematic approach to conduct the review. An extensive search was conducted of literature published between 1980 and 2019. A new exposure framework was developed to determine whether a study was sufficiently specific to TRAP, which included studies beyond the near-roadway environment. We performed random-effects meta-analysis when at least three estimates were available of an association between a specific exposure and outcome. We evaluated confidence in the evidence using a modified Office of Health Assessment and Translation (OHAT) approach, supplemented with a broader narrative synthesis.
Thirty-six cohort studies were included. Virtually all studies adjusted for a large number of individual and area-level covariates—including smoking, body mass index, and individual and area-level socioeconomic status—and were judged at a low or moderate risk for bias. Most studies were conducted in North America and Europe, and a few were based in Asia and Australia. The meta-analytic summary estimates for nitrogen dioxide, elemental carbon and fine particulate matter—pollutants with more than 10 studies—were 1.04 (95% CI 1.01, 1.06), 1.02 (1.00, 1.04) and 1.03 (1.01, 1.05) per 10, 1 and 5 µg/m3, respectively. Effect estimates are interpreted as the relative risk of mortality when the exposure differs with the selected increment. The confidence in the evidence for these pollutants was judged as high, because of upgrades for monotonic exposure–response and consistency across populations. The consistent findings across geographical regions, exposure assessment methods and confounder adjustment resulted in a high confidence rating using a narrative approach as well.
The overall confidence in the evidence for a positive association between long-term exposure to TRAP and non-accidental mortality was high.
Summary
Objectives
Growing evidence indicates that ambient (AAP: NO2, PM2.5 and O3) and traffic‐related air pollutants (TRAP) contribute to metabolic disease risk in adults; however, few studies have ...examined these relationships in children.
Methods
Metabolic profiling was performed in 429 overweight and obese African‐American and Latino youth living in urban Los Angeles, California. This cross‐sectional study estimated individual residential air pollution exposure and used linear regression to examine relationships between air pollution and metabolic outcomes.
Results
AAP and TRAP exposure were associated with adverse effects on glucose metabolism independent of body fat percent. PM2.5 was associated with 25.0% higher fasting insulin (p < 0.001), 8.3% lower insulin sensitivity (p < 0.001), 14.7% higher acute insulin response to glucose (p = 0.001) and 1.7% higher fasting glucose (p < 0.001). Similar associations were observed for increased NO2 exposure. TRAP from non‐freeway roads was associated with 12.1% higher insulin (p < 0.001), 6.9% lower insulin sensitivity (p = 0.02), 10.8% higher acute insulin response to glucose (p = 0.003) and 0.7% higher fasting glucose (p = 0.047).
Conclusions
Elevated air pollution exposure was associated with a metabolic profile that is characteristic of increased risk for type 2 diabetes. These results indicate that increased prior year exposure to air pollution may adversely affect type 2 diabetes‐related pathophysiology in overweight and obese minority children.
Exposures to ambient air pollutants have been associated with adverse birth outcomes. We investigated the effects of air pollutants on birth weight mediated by reduced fetal growth among term infants ...who were born in California during 1975-1987 and who participated in the Children's Health Study. Birth certificates provided maternal reproductive history and residence location at birth. Sociodemographic factors and maternal smoking during pregnancy were collected by questionnaire. Monthly average air pollutant levels were interpolated from monitors to the ZIP code of maternal residence at childbirth. Results from linear mixed-effects regression models showed that a 12-ppb increase in 24-hr ozone averaged over the entire pregnancy was associated with 47.2 g lower birth weight 95% confidence interval (CI), 27.4-67.0 g, and this association was most robust for exposures during the second and third trimesters. A 1.4-ppm difference in first-trimester carbon monoxide exposure was associated with 21.7 g lower birth weight (95% CI, 1.1-42.3 g) and 20% increased risk of intrauterine growth retardation (95% CI, 1.0-1.4). First-trimester CO and third-trimester O3exposures were associated with 20% increased risk of intrauterine growth retardation. A 20-μ g/ m3difference in levels of particulate matter ≤ 10 μm in aerodynamic diameter ( PM10) during the third trimester was associated with a 21.7-g lower birth weight (95% CI, 1.1-42.2 g), but this association was reduced and not significant after adjusting for O3. In summary, O3exposure during the second and third trimesters and CO exposure during the first trimester were associated with reduced birth weight.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A three-dimensional gas/aerosol atmospheric model is presented that predicts the size-resolved concentrations of all major primary and secondary components of atmospheric particulate matter (PM), ...including sulfate, nitrate, ammonium, chloride, sodium, elemental carbon, organic carbon, water, and crustal material. Aerosol size resolution is based on a sectional representation, typically extending from 0.01 to 10 μ for aerosols and from 0.01 to 30 μ when fog is present. The model is based on an internally mixed aerosol, wherein all particles in a specific size range are assumed to have the same chemical composition. Gas/aerosol equilibrium is computed based on the SEQUILIB algorithm of Pilinis and Seinfeld. An empirical fog model is included that approximates the effect of fogs on gas-phase photolysis rates, on aqueous-phase chemical reactions of sulfate and nitrate, and on the growth and shrinkage of the aerosol/fog droplet size distribution. The model is applied to simulate atmospheric conditions in the South Coast Air Basin of California during the 24–25 June 1987 episode of the Southern California Air Quality Study (SCAQS). The sensitivity of predicted aerosol levels to changes in source emissions is investigated.
The regional distribution of, and human exposure to, naphthalene are investigated for Southern California. A comprehensive approach is taken in which advanced models are linked for the first time to ...quantify population exposure to the emissions of naphthalene throughout Southern California. Naphthalene is the simplest and most abundant of the polycyclic aromatic hydrocarbons found in polluted urban environments, and has been detected in both outdoor and indoor air samples. Exposure to high concentrations of naphthalene may have adverse health effects, possibly causing cancer in humans. Among the significant emission sources are volatilization from naphthalene-containing products, petroleum refining, and combustion of fossil fuels and wood. Gasoline and diesel engine exhaust, with related vaporization from fuels, are found to contribute roughly half of the daily total naphthalene burden in Southern California. As part of this study, the emission inventory for naphthalene has been verified against new field measurements of the naphthalene-to-benzene ratio in a busy traffic tunnel in Los Angeles, supporting the modeling work carried out here.
The Surface Meteorology and Ozone Generation (SMOG) airshed model is used to compute the spatial and temporal distributions of naphthalene and its photooxidation products in Southern California. The present simulations reveal a high degree of spatial variability in the concentrations of naphthalene-related species, with large diurnal and seasonal variations as well. Peak naphthalene concentrations are estimated to occur in the early morning hours in the winter season. The naphthalene concentration estimates obtained from the SMOG model are employed in the Regional Human Exposure (REHEX) model to calculate population exposure statistics. Results show average hourly naphthalene exposures in Southern California under summer and winter conditions of 270 and 430
ng
m
−3, respectively. Exposure to significantly higher concentrations may occur for individuals close to local sources, or in naphthalene “hotspots” revealed by simulations and observations. Such levels of naphthalene exposure may be used to gauge the potential health impacts of long-term naphthalene exposure. Results are also given for the distributions of 1,4-naphthoquinone, a naphthalene reaction product that may have significant health effects.
Increased interest in the health effects of ambient par-ticulate mass (PM) has focused attention on the evaluation of existing mass measurement methodologies and the definition of PM in ambient air. ...The Rupprecht and Patashnick Tapered Element Oscillating MicroBalance (TEOM
®
) method for PM is compared with time-integrated gravimetric (manual) PM methods in large urban areas during different seasons. Comparisons are conducted for both PM
10
and PM
2.5
concentrations.
In urban areas, a substantial fraction of ambient PM can be semi-volatile material. A larger fraction of this component of PM
10
may be lost from the TEOM-heated filter than the Federal Reference Method (FRM). The observed relationship between TEOM and FRM methods varied widely among sites and seasons. In East Coast urban areas during the summer, the methods were highly correlated with good agreement. In the winter, correlation was somewhat lower, with TEOM PM concentrations generally lower than the FRM. Rubidoux, CA, and two Mexican sites (Tlalnepantla and Merced) had the highest levels of PM
10
and the largest difference between TEOM and manual methods.
PM
2.5
data from collocation of 24-hour manual samples with the TEOM are also presented. As most of the semi-volatile PM is in the fine fraction, differences between these methods are larger for PM
2.5
than for PM
10
.
This paper reviews and compares two air quality benefit assessments completed for California's South Coast Air Basin in 1989 and 2008. Specifically, we separate the influence of changes in population ...and air quality from that of newer health concentration–response relationships and changing economic values. The dynamic interaction of key variables, including health and economic, as well as changes in population and air quality, lead to significant changes in results over time. Results show dramatic reductions in exposures to ozone and particulate concentrations between the two time periods, a continually evolving health literature, and in contrast, fairly constant real economic unit values assigned to adverse health outcomes. Such research is important because highly technical analyses of the expected benefits of proposed air quality regulatory programs have become an increasingly important component of many decision-making processes.
Summary Background Whether local exposure to major roadways adversely affects lung-function growth during the period of rapid lung development that takes place between 10 and 18 years of age is ...unknown. This study investigated the association between residential exposure to traffic and 8-year lung-function growth. Methods In this prospective study, 3677 children (mean age 10 years SD 0·44) participated from 12 southern California communities that represent a wide range in regional air quality. Children were followed up for 8 years, with yearly lung-function measurements recorded. For each child, we identified several indicators of residential exposure to traffic from large roads. Regression analysis was used to establish whether 8-year growth in lung function was associated with local traffic exposure, and whether local traffic effects were independent of regional air quality. Findings Children who lived within 500 m of a freeway (motorway) had substantial deficits in 8-year growth of forced expiratory volume in 1 s (FEV1 , −81 mL, p=0·01 95% CI −143 to −18) and maximum midexpiratory flow rate (MMEF, −127 mL/s, p=0·03 −243 to −11), compared with children who lived at least 1500 m from a freeway. Joint models showed that both local exposure to freeways and regional air pollution had detrimental, and independent, effects on lung-function growth. Pronounced deficits in attained lung function at age 18 years were recorded for those living within 500 m of a freeway, with mean percent-predicted 97·0% for FEV1 (p=0·013, relative to >1500 m 95% CI 94·6–99·4) and 93·4% for MMEF (p=0·006 95% CI 89·1–97·7). Interpretation Local exposure to traffic on a freeway has adverse effects on children's lung development, which are independent of regional air quality, and which could result in important deficits in attained lung function in later life.
Many regions worldwide are experiencing rapid urbanization, and often along with growth in the local economy and population comes worsening air quality. Such regions typically find that addressing ...the additional challenge of polluted air is difficult. This paper reports the results of an assessment of the present health and related economic costs of poor air quality in the San Joaquin Valley of California. Further, it suggests how such assessments can support strategies to pursue pollution reductions that offer the largest near-term gains, by rigorously modeling the associations between pollution levels, demographic groups, and recognized adverse health effects.
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