Evaluation of air quality indicators in Alberta,Canada – An international perspective

There has been an increase in oil sands development in northern Alberta, Canada and an overall increase in economic activity in the province in recent years. An evaluation of the state of air quality was conducted in four Alberta locations – urban centers of Calgary and Edmonton, and smaller communities of Fort McKay and Fort McMurray in the Athabasca Oil Sands Region (AOSR). Concentration trends, diurnal hourly and monthly average concentration profiles, and exceedances of provincial, national and international air quality guidelines were assessed for several criteria air pollutants over the period 1998 to 2014. Two methods were used to evaluate trends. Parametric analysis of annual median 1 h concentrations and non-parametric analysis of annual geometric mean 1 h concentrations showed consistent decreasing trends for NO₂ and SO₂ (< 1 ppb per year), CO (< 0.1 ppm per year) at all stations, decreasing for THC (< 0.1 ppm per year) and increasing for O₃ (≤ 0.52 ppb per year) at most stations and unchanged for PM_2.5 at all stations in Edmonton and Calgary over a 17-year period. Little consistency in trends was observed among the methods for the same air pollutants other than for THC (increasing in Fort McKay < 0.1 ppm per year and no trend in Fort McMurray), PM_2.5 in Fort McKay and Fort McMurray (no trend) and CO (decreasing < 0.1 ppm per year in Fort McMurray) over the same period. Levels of air quality indicators at the four locations were compared with other Canadian and international urban areas to judge the current state of air quality. Median and annual average concentrations for Alberta locations tended to be the smallest in Fort McKay and Fort McMurray. Other than for PM_2.5, Calgary and Edmonton tended to have median and annual average concentrations comparable to and/or below that of larger populated Canadian and U.S. cities, depending upon the air pollutant.     

Twelve-year trends in ambient concentrations of volatile organic compounds in a community of the Alberta Oil Sands Region,Canada

Environmental exposure to volatile organic compounds (VOCs) in ambient air is one of a number of concerns that the First Nation Community of Fort McKay, Alberta has related to development of Canada's oil sands. An in-depth investigation of trends in ambient air VOC levels in Fort McKay was undertaken to better understand the role and possible significance of emissions from Alberta's oil sands development. A non-parametric trend detection method was used to investigate trends in emissions and ambient VOC concentrations over a 12-year (2001 − 2012) period. Relationships between ambient VOC concentrations and production indicators of oil sands operations around Fort McKay were also examined. A weak upward trend (significant at 90% confidence level) was found for ambient concentrations of total VOCs based on sixteen detected species with an annual increase of 0.64 μg/m³ (7.2%) per year (7.7 μg/m³ increase per decade). Indicators of production (i.e., annual bitumen production and mined oil sands quantities) were correlated with ambient total VOC concentrations. Only one of 29 VOC species evaluated (1-butene) showed a statistically significant upward trend (p = 0.05). Observed geometric (arithmetic) mean and maximum ambient concentrations of selected VOCs of public health concern for most recent three years of the study period (2010 − 2012) were below chronic and acute health risk screening criteria of the U.S. Agency for Toxic Substances and Disease Registry and U.S. Environmental Protection Agency. Thirty-two VOCs are recommended for tracking in future air quality investigations in the community to better understand whether changes are occurring over time in relation to oil sands development activities and to inform policy makers about whether or not these changes warrant additional attention.     

Health burdens of surface ozone in the UK for a range of future scenarios

Exposure to surface ozone (O₃), which is influenced by emissions of precursor chemical species, meteorology and population distribution, is associated with excess mortality and respiratory morbidity. In this study, the EMEP-WRF atmospheric chemistry transport model was used to simulate surface O₃ concentrations at 5 km horizontal resolution over the British Isles for a baseline year of 2003, for three anthropogenic emissions scenarios for 2030, and for a + 5 °C increase in air temperature on the 2003 baseline. Deaths brought forward and hospitalisation burdens for 12 UK regions were calculated from population-weighted daily maximum 8-hour O₃. The magnitude of changes in annual mean surface O₃ over the UK for + 5 °C temperature (+ 1.0 to + 1.5 ppbv, depending on region) was comparable to those due to inter-annual meteorological variability (− 1.5 to + 1.5 ppbv) but considerably less than changes due to precursor emissions changes by 2030 (− 3.0 to + 3.5 ppbv, depending on scenario and region). Including population changes in 2030, both the ‘current legislation’ and ‘maximum feasible reduction’ scenarios yield greater O₃-attributable health burdens than the ‘high’ emission scenario: + 28%, + 22%, and + 16%, respectively, above 2003 baseline deaths brought forward (11,500) and respiratory hospital admissions (30,700), using O₃ exposure over the full year and no threshold for health effects. The health burdens are greatest under the ‘current legislation’ scenario because O₃ concentrations increase as a result of both increases in background O₃ concentration and decreases in UK NO_x emissions. For the + 5 °C scenario, and no threshold (and not including population increases), total UK health burden increases by 500 premature deaths (4%) relative to the 2003 baseline. If a 35 ppbv threshold for O₃ effects is assumed, health burdens are more sensitive to the current legislation and + 5 °C scenarios, although total health burdens are roughly an order of magnitude lower. In all scenarios, the assumption of a threshold increases the proportion of health burden in the south and east of the UK compared with the no threshold assumption. The study highlights that the total, and geographically-apportioned, O₃-attributable health burdens in the UK are highly sensitive to the future trends of hemispheric, regional and local emissions of O₃ precursors, and to the assumption of a threshold for O₃ effect.     

Fate,distribution, and contrasting temporal trends of perfluoroalkyl substances (PFASs) in Lake Ontario,Canada

Lake Ontario water and sediment collected from tributary, nearshore, and open lake sites were analyzed for perfluoroalkyl substances (PFASs), namely perfluoroalkyl carboxylic acids (PFCAs, F(CF₂)_nCO₂⁻; n = 6-11,13) and perfluoroalkane sulfonic acids (PFSAs, F(CF₂)_nSO₃⁻; n = 6,8,10). Survey results of surface sediment and water indicated that shorter chained PFASs were predominant in and near urban/industrial area watersheds, while longer chained PFASs were predominant in fine-grained sediment from major depositional basins. Niagara River suspended solids (1981–2006) demonstrated temporal trends that may have been influenced by recent changes in North American production and use of PFASs. Perfluorooctane sulfonate (PFOS) reached a peak concentration in 2001 of 1.1 ng/g, followed by a decrease from 2001 to 2006 (half-life = 9 years). Perfluorooctanoic acid (PFOA) increased from 2001 to 2006 (doubling time = 2 years) reaching a peak concentration of 0.80 ng/g. In contrast, three sediment cores from western, central, and eastern Lake Ontario showed increasing temporal trends to surface sediment for all PFASs. PFOA and PFOS concentrations increased from 1988 to 2004 (doubling time = ~ 4 years) in the western Lake Ontario core. The observed variations in temporal trends from different environmental compartments may be a result of the physico-chemical properties of PFASs, ongoing emissions, and the environmental transformation and degradation of PFAS precursor compounds.     

Respiratory hospital admissions in young children living near metal smelters,pulp mills and oil refineries in two Canadian provinces

BackgroundIndustrial plants emit air pollutants like fine particles (PM2.5), sulfur dioxide (SO2) and nitrogen dioxide (NO2) that may affect the health of individuals living nearby.ObjectiveTo assess the effects of community exposure to air emissions of PM2.5, SO2, and NO2 from pulp mills, oil refineries, metal smelters, on respiratory hospital admissions in young children in Quebec (QC) and British Columbia (BC), Canada.MethodsWe assessed QC, BC and pooled associations between the following estimates of exposure and hospital admissions for asthma and bronchiolitis in children aged 2–4 years for the years 2002–2010: i) Crude emission exposures at the residential postal codes of children, calculated by multiplying estimated daily emissions of PM2.5, SO2, or NO2 from all nearby (< 7.5 km) pulp mills, oil refineries, metal smelters emitting yearly ≥ 50 t and their total emissions, by the percent of the day each postal code was downwind; ii) Daily levels of these pollutants at central ambient monitoring stations nearby the industries and the children's residences.ResultsSeventy-one major industries were selected between QC and BC, with a total of 2868 cases included in our analyses. More cases were exposed to emissions from major industries in QC than in BC (e.g. 2505 admissions near SO2 industrial emitters in QC vs 334 in BC), although air pollutant levels were similar. Odds ratios (ORs) for crude refinery and smelter emissions were positive in QC but more variable in BC. For example with PM2.5 in QC, ORs were 1.13 per 0.15 t/day (95% CI: 1.00–1.27) and 1.03 (95% CI: 0.99–1.07) for refinery and smelter emissions, respectively. Pooled results of QC and BC for crude total SO2 emissions from all sources indicated a 1% increase (0–3%) in odds of hospital admissions per 1.50 t/day increase in exposure. Associations with measured pollutant levels were only seen in BC, with SO2 and NO2.ConclusionHospital admissions for wheezing diseases in young children were associated with community exposure to industrial air pollutant emissions. Future work is needed to better assess the risk of exposure to complex mixture of air pollutants from multiple industrial sources.     

Estimation of exposure to atmospheric pollutants during pregnancy integrating space–time activity and indoor air levels: Does it make a difference?

Studies of air pollution effects during pregnancy generally only consider exposure in the outdoor air at the home address. We aimed to compare exposure models differing in their ability to account for the spatial resolution of pollutants, space–time activity and indoor air pollution levels. We recruited 40 pregnant women in the Grenoble urban area, France, who carried a Global Positioning System (GPS) during up to 3 weeks; in a subgroup, indoor measurements of fine particles (PM_2.5) were conducted at home (n = 9) and personal exposure to nitrogen dioxide (NO₂) was assessed using passive air samplers (n = 10). Outdoor concentrations of NO₂, and PM_2.5 were estimated from a dispersion model with a fine spatial resolution. Women spent on average 16 h per day at home. Considering only outdoor levels, for estimates at the home address, the correlation between the estimate using the nearest background air monitoring station and the estimate from the dispersion model was high (r = 0.93) for PM_2.5 and moderate (r = 0.67) for NO₂. The model incorporating clean GPS data was less correlated with the estimate relying on raw GPS data (r = 0.77) than the model ignoring space–time activity (r = 0.93). PM_2.5 outdoor levels were not to moderately correlated with estimates from the model incorporating indoor measurements and space–time activity (r = − 0.10 to 0.47), while NO₂ personal levels were not correlated with outdoor levels (r = − 0.42 to 0.03). In this urban area, accounting for space–time activity little influenced exposure estimates; in a subgroup of subjects (n = 9), incorporating indoor pollution levels seemed to strongly modify them.     

Health impact metrics for air pollution management strategies

Health impact assessments (HIAs) inform policy and decision making by providing information regarding future health concerns, and quantitative HIAs now are being used for local and urban-scale projects. HIA results can be expressed using a variety of metrics that differ in meaningful ways, and guidance is lacking with respect to best practices for the development and use of HIA metrics. This study reviews HIA metrics pertaining to air quality management and presents evaluative criteria for their selection and use. These are illustrated in a case study where PM_2.5 concentrations are lowered from 10 to 8 μg/m³ in an urban area of 1.8 million people. Health impact functions are used to estimate the number of premature deaths, unscheduled hospitalizations and other morbidity outcomes. The most common metric in recent quantitative HIAs has been the number of cases of adverse outcomes avoided. Other metrics include time-based measures, e.g., disability-adjusted life years (DALYs), monetized impacts, functional-unit based measures, e.g., benefits per ton of emissions reduced, and other economic indicators, e.g., cost-benefit ratios. These metrics are evaluated by considering their comprehensiveness, the spatial and temporal resolution of the analysis, how equity considerations are facilitated, and the analysis and presentation of uncertainty. In the case study, the greatest number of avoided cases occurs for low severity morbidity outcomes, e.g., asthma exacerbations (n = 28,000) and minor-restricted activity days (n = 37,000); while DALYs and monetized impacts are driven by the severity, duration and value assigned to a relatively low number of premature deaths (n = 190 to 230 per year). The selection of appropriate metrics depends on the problem context and boundaries, the severity of impacts, and community values regarding health. The number of avoided cases provides an estimate of the number of people affected, and monetized impacts facilitate additional economic analyses useful to policy analysis. DALYs are commonly used as an aggregate measure of health impacts and can be used to compare impacts across studies. Benefits per ton metrics may be appropriate when changes in emissions rates can be estimated. To address community concerns and HIA objectives, a combination of metrics is suggested.     

Exposure to emissions from municipal solid waste incinerators and miscarriages: A multisite study of the MONITER Project

BackgroundMiscarriages are an important indicator of reproductive health but only few studies have analyzed their association with exposure to emissions from municipal solid waste incinerators.This study analyzed the occurrence of miscarriages in women aged 15–49 years residing near seven incinerators of the Emilia-Romagna Region (Northern Italy) in the period 2002–2006.MethodsWe considered all pregnancies occurring in women residing during the first trimester of pregnancy within a 4 km radius of each incinerator. Addresses were geocoded and exposures were characterized by a dispersion model (ADMS Urban model) producing pollution maps for incinerators based on PM₁₀ stack measurements and for other pollution sources based on NO_x ground measurements. Information on pregnancies and their outcomes was obtained from the Hospital Discharge Database. Simplified True Abortion Risks (STAR) × 100 estimated pregnancies were calculated. We ran logistic regressions adjusting for maternal characteristics, exposure to other sources of pollution, and sites, considering the whole population and stratifying by miscarriage history.ResultsThe study analyzed 11,875 pregnancies with 1375 miscarriages. After adjusting for confounders, an increase of PM₁₀ due to incinerator emissions was associated with an increased risk of miscarriage (test for trend, p = 0.042). The odds ratio for the highest quartile of exposed versus not exposed women was 1.29, 95% CI 0.97–1.72. The effect was present only for women without previous miscarriages (highest quartile of exposed versus not exposed women 1.44, 95% CI 1.06–1.96; test for trend, p = 0.009).ConclusionExposure to incinerator emissions is associated with an increased risk of miscarriage. This result should be interpreted with those of a previous study on reproductive health conducted in the same area that observed an association between incinerator exposure and preterm births.     

Three decades (1983–2010) of contaminant trends in East Greenland polar bears (Ursus maritimus). Part 2: Brominated flame retardants

Brominated flame retardants were determined in adipose tissues from 294 polar bears (Ursus maritimus) sampled in East Greenland in 23 of the 28 years between 1983 and 2010. Significant linear increases were found for sum polybrominated diphenyl ether (ΣPBDE), BDE100, BDE153, and hexabromocyclododecane (HBCD). Average increases of 5.0% per year (range: 2.9–7.6%/year) were found for the subadult polar bears. BDE47 and BDE99 concentrations did not show a significant linear trend over time, but rather a significant non-linear trend peaking between 2000 and 2004. The average ΣPBDE concentrations increased 2.3 fold from 25.0 ng/g lw (95% C.I.: 15.3–34.7 ng/g lw) in 1983–1986 to 58.5 ng/g lw (95% C.I.: 43.6–73.4 ng/g lw) in 2006–2010. Similar but fewer statistically significant trends were found for adult females and adult males likely due to smaller sample size and years. Analyses of δ¹⁵N and δ¹³C stable isotopes in hair revealed no clear linear temporal trends in trophic level or carbon source, respectively, and non-linear trends differed among sex and age groups. These increasing concentrations of organobromine contaminants contribute to complex organohalogen mixture, already causing health effects to the East Greenland polar bears.     

The urban rise and fall of air lead (Pb) and the latent surge and retreat of societal violence

We evaluate air Pb emissions and latent aggravated assault behavior at the scale of the city. We accomplish this by regressing annual Federal Bureau of Investigation aggravated assault rate records against the rise and fall of annual vehicle Pb emissions in Chicago (Illinois), Indianapolis (Indiana), Minneapolis (Minnesota), San Diego (California), Atlanta (Georgia), and New Orleans (Louisiana). Other things held equal, a 1% increase in tonnages of air Pb released 22 years prior raises the present period aggravated assault rate by 0.46% (95% CI, 0.28 to 0.64). Overall our model explains 90% of the variation in aggravated assault across the cities examined. In the case of New Orleans, 85% of temporal variation in the aggravated assault rate is explained by the annual rise and fall of air Pb (total = 10,179 metric tons) released on the population of New Orleans 22 years earlier. For every metric ton of Pb released 22 years prior, a latent increase of 1.59 (95% CI, 1.36 to 1.83, p < 0.001) aggravated assaults per 100,000 were reported. Vehicles consuming fuel containing Pb additives contributed much larger quantities of Pb dust than generally recognized. Our findings along with others predict that prevention of children's lead exposure from lead dust now will realize numerous societal benefits two decades into the future, including lower rates of aggravated assault.     

Association between background exposure to organochlorine pesticides and the risk of cognitive impairment: A prospective study that accounts for weight change

BackgroundBackground exposure to organochlorine (OC) pesticides was recently linked to cognitive impairment and dementia in cross-sectional and case–control studies. This prospective study was performed to evaluate if OC pesticides at baseline are associated with the future risk of cognitive impairment in elderly, with particular focus on weight change.MethodsPlasma concentrations of 3 OC pesticides (p,p′-DDE, trans-nonachlor, and hexachlorobenzene) were measured among 989 men and women aged 70 years in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). Cognitive impairment was validated by reviewing medical records. During the ten year follow-up, cognitive impairment was developed in 75 subjects. When weight change from age 70 to 75 was considered in analyses, elderly with incident cases before age 75 were excluded to keep the prospective perspective, leaving 795 study subjects and 44 incident cases.ResultsThe summary measure of 3 OC pesticides predicted the development of cognitive impairment after adjusting for covariates, including weight change. Compared to subjects with OC pesticides < 25th percentile, adjusted hazard ratios (HRs) in those with 25th–<75th and ≥ 75th percentiles were 3.5 (95% confidence interval: 1.5–8.5) and 3.2 (1.1–7.6), respectively (P_trend = 0.04). Among 506 subjects who maintained or gained body weight, adjusted HRs were 6.9 and 11.6 (1.4–92.6) among the elderly in the 25th–<75th and ≥ 75th percentiles compared to < 25th percentile (P_trend < 0.01).ConclusionsThis prospective study demonstrates that background exposure to OC pesticides are linked to the risk of developing cognitive impairment in elderly. The role of the chronic exposure to low dose OC pesticides in the development of dementia should be further evaluated in other populations.     

Combustion particles emitted during church services: Implications for human respiratory health

Burning candles and incense generate particulate matter (PM) that produces poor indoor air quality and may cause human pulmonary problems. This study physically characterised combustion particles collected in a church during services. In addition, the emissions from five types of candles and two types of incense were investigated using a combustion chamber. The plasmid scission assay was used to determine the oxidative capacities of these church particles. The corresponding risk factor (CRf) was derived from the emission factor (Ef) and the oxidative DNA damage, and used to evaluate the relative respiratory exposure risks. Real-time PM measurements in the church during candle–incense burning services showed that the levels (91.6 μg/m³ for PM₁₀; 38.9 μg/m³ for PM_2.5) exceeded the European Union (EU) air quality guidelines. The combustion chamber testing, using the same environmental conditions, showed that the incense Ef for both PM₁₀ (490.6–587.9 mg/g) and PM_2.5 (290.1–417.2 mg/g) exceeded that of candles; particularly the PM_2.5 emissions. These CRf results suggested that the exposure to significant amounts of incense PM could result in a higher risk of oxidative DNA adducts (27.4–32.8 times) than tobacco PM. The generation and subsequent inhalation of PM during church activities may therefore pose significant risks in terms of respiratory health effects.     

Temporal trends in concentrations and total serum burdens of organochlorine compounds from birth until adolescence and the role of breastfeeding

Introduction: The aims of the present study are to assess the temporal trends of organochlorine compounds (OCs) concentrations and total serum burdens from birth until adolescence and the influence of breastfeeding in these temporal trends. Methods: In 1997 two birth cohort studies were set up in Ribera d'Ebre (N = 102) and the island of Menorca (N = 482), Spain. Concentrations (ng/mL) of OCs [pentachlorobenzene (PeCB), four isomers of hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (4,4′-DDT), dichlorodiphenyldichloroethylene (4,4′-DDE) and seven polychlorobiphenyl congeners (Σ₇PCBs)] were measured in cord blood and at the age of 4 and 14 years. The total serum burdens (ng) of these compounds were estimated based on the total blood volume (mL) of children at the different ages. We compared median concentrations and total serum burdens of these OCs at the different time-points of follow-up between children of Ribera d'Ebre and Menorca and between breastfed and non-breastfed children. Results: From birth until adolescence concentrations of all OCs drastically reduced. These reductions were mainly derived from the dilution of OCs, associated to an increase in total blood volume of children at the age of 4 and 14 years. Despite the reduction in OCs concentrations, the total serum burdens of 4,4′-DDE and Σ₇PCBs, were higher in adolescents than at birth. Increases in OCs total serum burden occurred both in breastfed and non-breastfed children, but were significantly higher in the first. Conclusions: Even after decades of banning OCs production and use, current young generations in westernized countries are still bioaccumulating these compounds. Given the potential health effects of OCs, especial attention should be paid in the control of secondary emissions in the environment and in the control of food production and contamination. In countries with endemic malaria it is important to work towards effective alternatives to the use of DDT.     

The mortality effect of ship-related fine particulate matter in the Sydney greater metropolitan region of NSW,Australia

This study investigates the mortality effect of primary and secondary PM_2.5 related to ship exhaust in the Sydney greater metropolitan region of Australia. A detailed inventory of ship exhaust emissions was used to model a) the 2010/11 concentration of ship-related PM_2.5 across the region, and b) the reduction in PM_2.5 concentration that would occur if ships used distillate fuel with a 0.1% sulfur content at berth or within 300 km of Sydney. The annual loss of life attributable to 2010/11 levels of ship-related PM_2.5 and the improvement in survival associated with use of low-sulfur fuel were estimated from the modelled concentrations.In 2010/11, approximately 1.9% of the region-wide annual average population weighted-mean concentration of all natural and human-made PM_2.5 was attributable to ship exhaust, and up to 9.4% at suburbs close to ports. An estimated 220 years of life were lost by people who died in 2010/11 as a result of ship exhaust-related exposure (95% CI_β: 140–290, where CI_β is the uncertainty in the concentration-response coefficient only). Use of 0.1% sulfur fuel at berth would reduce the population weighted-mean concentration of PM_2.5 related to ship exhaust by 25% and result in a gain of 390 life-years over a twenty year period (95% CI_β: 260–520). Use of 0.1% sulfur fuel within 300 km of Sydney would reduce the concentration by 56% and result in a gain of 920 life-years over twenty years (95% CI_β: 600–1200).Ship exhaust is an important source of human exposure to PM_2.5 in the Sydney greater metropolitan region. This assessment supports intervention to reduce ship emissions in the GMR. Local strategies to limit the sulfur content of fuel would reduce exposure and will become increasingly beneficial as the shipping industry expands. A requirement for use of 0.1% sulfur fuel by ships within 300 km of Sydney would provide more than twice the mortality benefit of a requirement for ships to use 0.1% sulfur fuel at berth.     

Traffic-related air pollution and hyperactivity/inattention,dyslexia and dyscalculia in adolescents of the German GINIplus and LISAplus birth cohorts

BackgroundFew studies have examined the link between air pollution exposure and behavioural problems and learning disorders during late childhood and adolescence.ObjectivesTo determine whether traffic-related air pollution exposure is associated with hyperactivity/inattention, dyslexia and dyscalculia up to age 15 years using the German GINIplus and LISAplus birth cohorts (recruitment 1995–1999).MethodsHyperactivity/inattention was assessed using the German parent-completed (10 years) and self-completed (15 years) Strengths and Difficulties Questionnaire. Responses were categorized into normal versus borderline/abnormal. Parent-reported dyslexia and dyscalculia (yes/no) at age 10 and 15 years were defined using parent-completed questionnaires. Individual-level annual average estimates of nitrogen dioxide (NO₂), particulate matter (PM)₁₀ mass, PM_2.5 mass and PM_2.5 absorbance concentrations were assigned to each participant's birth, 10 year and 15 year home address. Longitudinal associations between the air pollutants and the neurodevelopmental outcomes were assessed using generalized estimation equations, separately for both study areas, and combined in a random-effects meta-analysis. Odds ratios and 95% confidence intervals are given per interquartile range increase in pollutant concentration.ResultsThe prevalence of abnormal/borderline hyperactivity/inattention scores and parental-reported dyslexia and dyscalculia at 15 years of age was 12.9%, 10.5% and 3.4%, respectively, in the combined population (N = 4745). In the meta- analysis, hyperactivity/inattention was associated with PM_2.5 mass estimated to the 10 and 15 year addresses (1.12 [1.01, 1.23] and 1.11 [1.01, 1.22]) and PM_2.5 absorbance estimated to the 10 and 15 year addresses (1.14 [1.05, 1.25] and 1.13 [1.04, 1.23], respectively).ConclusionsWe report associations suggesting a potential link between air pollution exposure and hyperactivity/inattention scores, although these findings require replication.     

Short-term effects of air pollution on respiratory morbidity at Rio de Janeiro — Part II: Health assessment

The effects of air pollution on health have been studied worldwide. Given that air pollution triggers oxidative stress and inflammation, it is plausible that high levels of air pollutants cause higher number of hospitalisations. This study aimed to assess the impact of air pollution on the emergency hospitalisation for respiratory disease in Rio de Janeiro, Brazil. The study was divided in two parts: Part I specifically addressing the air pollution assessment and Part II addressing the health assessment. Accordingly, this Part II aimed to estimate the association between the concentrations of PM₁₀, SO₂ and CO observed in Rio de Janeiro and the number of emergency hospitalisations at a central hospital due to respiratory diseases. The pollutant concentrations were measured at two different sites in Rio de Janeiro, but the excess relative risks were calculated based on the concentrations observed at one of the sites, where limits were generally exceeded more frequently, between September 2000 and December 2005. A time series analysis was performed using the number of hospitalisations, divided in three categories (children until 1 year old, children aged between 1 and 5 years old and elderly with 65 years old or more) as independent variable, the concentrations of pollutants as dependent variables and temperature, relative humidity, long term trend, and seasonality as confounders. Data were analysed using generalised additive models with smoothing for some of the dependent variables. Results showed an excess risk of hospitalisation for respiratory disease higher than 2% per 10 μg m^− 3 increase in PM₁₀ concentrations for children under 5 years old, of 2% per 10 μg m^− 3 increase in SO₂ for elderly above 65 years old and around 0.1% per 10 μg m^− 3 increase in CO for children under 1 year and elderly. Other studies have found associations that are in agreement with the results achieved in this study.The study suggests that the ambient levels of air pollutants experienced in Rio de Janeiro between 2000 and 2005 were linked to the number of hospitalisations for respiratory diseases among children and elderly.     

Spatiotemporal analysis and human exposure assessment on polycyclic aromatic hydrocarbons in indoor air,settled house dust,and diet: A review

This review summarizes the published literature on the presence of polycyclic aromatic hydrocarbons (PAH) in indoor air, settled house dust, and food, and highlights geographical and temporal trends in indoor PAH contamination. In both indoor air and dust, ΣPAH concentrations in North America have decreased over the past 30 years with a halving time of 6.7 ± 1.9 years in indoor air and 5.0 ± 2.3 years in indoor dust. In contrast, indoor PAH concentrations in Asia have remained steady. Concentrations of ΣPAH in indoor air are significantly (p < 0.01) higher in Asia than North America. In studies recording both vapor and particulate phases, the global average concentration in indoor air of ΣPAH excluding naphthalene is between 7 and 14,300 ng/m³. Over a similar period, the average ΣPAH concentration in house dust ranges between 127 to 115,817 ng/g. Indoor/outdoor ratios of atmospheric concentrations of ΣPAH have declined globally with a half-life of 6.3 ± 2.3 years. While indoor/outdoor ratios for benzo[a]pyrene toxicity equivalents (BaP_eq) declined in North America with a half-life of 12.2 ± 3.2 years, no significant decline was observed when data from all regions were considered. Comparison of the global database, revealed that I/O ratios for ΣPAH (average = 4.3 ± 1.3), exceeded significantly those of BaP_eq (average = 1.7 ± 0.4) in the same samples. The significant decline in global I/O ratios suggests that indoor sources of PAH have been controlled more effectively than outdoor sources. Moreover, the significantly higher I/O ratios for ΣPAH compared to BaP_eq, imply that indoor sources of PAH emit proportionally more of the less carcinogenic PAH than outdoor sources. Dietary exposure to PAH ranges from 137 to 55,000 ng/day. Definitive spatiotemporal trends in dietary exposure were precluded due to relatively small number of relevant studies. However, although reported in only one study, PAH concentrations in Chinese diets exceeded those in diet from other parts of the world, a pattern consistent with the spatial trends observed for concentrations of PAH in indoor air. Evaluation of human exposure to ΣPAH via inhalation, dust and diet ingestion, suggests that while intake via diet and inhalation exceeds that via dust ingestion; all three pathways contribute and merit continued assessment.     

Using air quality modeling to study source–receptor relationships between nitrogen oxides emissions and ozone exposures over the United States

Human exposure to ambient ozone (O₃) has been linked to a variety of adverse health effects. The ozone level at a location is contributed by local production, regional transport, and background ozone. This study combines detailed emission inventory, air quality modeling, and census data to investigate the source–receptor relationships between nitrogen oxides (NO_x) emissions and population exposure to ambient O₃ in 48 states over the continental United States. By removing NO_x emissions from each state one at a time, we calculate the change in O₃ exposures by examining the difference between the base and the sensitivity simulations. Based on the 49 simulations, we construct state-level and census region-level source–receptor matrices describing the relationships among these states/regions. We find that, for 43 receptor states, cumulative NO_x emissions from upwind states contribute more to O₃ exposures than the state's own emissions. In-state emissions are responsible for less than 15% of O₃ exposures in 90% of U.S. states. A state's NO_x emissions can influence 2 to 40 downwind states by at least a 0.1 ppbv change in population-averaged O₃ exposure. The results suggest that the U.S. generally needs a regional strategy to effectively reduce O₃ exposures. But the current regional emission control program in the U.S. is a cap-and-trade program that assumes the marginal damage of every ton of NO_x is equal. In this study, the average O₃ exposures caused by one ton of NO_x emissions ranges from ? 2.0 to 2.3 ppm-people-hours depending on the state. The actual damage caused by one ton of NO_x emissions varies considerably over space.     

Air pollution exposure and telomere length in highly exposed subjects in Beijing,China: A repeated-measure study

BackgroundAmbient particulate matter (PM) exposure has been associated with short- and long-term effects on cardiovascular disease (CVD). Telomere length (TL) is a biomarker of CVD risk that is modified by inflammation and oxidative stress, two key pathways for PM effects. Whether PM exposure modifies TL is largely unexplored.ObjectivesTo investigate effects of PM on blood TL in a highly-exposed population.MethodsWe measured blood TL in 120 blood samples from truck drivers and 120 blood samples from office workers in Beijing, China. We measured personal PM_2.5 and Elemental Carbon (EC, a tracer of traffic particles) using light-weight monitors. Ambient PM₁₀ was obtained from local monitoring stations. We used covariate-adjusted regression models to estimate percent changes in TL per an interquartile-range increase in exposure.ResultsCovariate-adjusted TL was higher in drivers (mean = 0.87, 95%CI: 0.74; 1.03) than in office workers (mean = 0.79, 95%CI: 0.67; 0.93; p = 0.001). In all participants combined, TL increased in association with personal PM_2.5 (+ 5.2%, 95%CI: 1.5; 9.1; p = 0.007), personal EC (+ 4.9%, 95%CI: 1.2; 8.8; p = 0.01), and ambient PM₁₀ (+ 7.7%, 95%CI: 3.7; 11.9; p < 0.001) on examination days. In contrast, average ambient PM₁₀ over the 14 days before the examinations was significantly associated with shorter TL (− 9.9%, 95%CI: − 17.6; − 1.5; p = 0.02).ConclusionsShort-term exposure to ambient PM is associated with increased blood TL, consistent with TL roles during acute inflammatory responses. Longer exposures may shorten TL as expected after prolonged pro-oxidant exposures. The observed TL alterations may participate in the biological pathways of short- and long-term PM effects.     

Sorption of trihalomethanes in foods

Trihalomethanes (THMs, namely, CHCl₃, CHCl₂Br, CHClBr₂ and CHBr₃) are disinfection by-products that are present in drinking water. These toxic chemicals are also present in meat, dairy products, vegetables, baked goods, beverages and other foods, although information regarding their concentrations and origin is very limited. This study investigates sorption of THMs occurring during rinsing and cooking of foods and the significance of food as an exposure source.Initial estimates of THM uptake were measured in experiments representing rinsing with tap water at 25 C using nine types of food, and for cooking in tap water at 90 C for fourteen other foods. A subset of foods was then selected for further study over a range of THM concentrations (23.7–118.7 μg/l), temperatures (25 C and 90 C), food concentrations (0.2–1.4, food weight: water weight), and contact times (5–240 min). Data were analyzed using regression and exponential models, and diffusion models were used to help explain the trends of THM uptake.Among vegetables, sorbed THM concentrations at 25 C were 213 to 774 ng/g for CHCl₃, 53 to 609 ng/g for CHCl₂Br, and 150–845 ng/g for CHClBr₂. Meats at 90 C tended to have higher concentrations, e.g., 870–2634 ng/g for CHCl₃. Sorbed concentrations increased with contact time and THM concentration, and decreased with food concentration in rinsing tests (using spinach, iceberg-head lettuce and cauliflower) and cooking tests (using tomato, potato, beef and miso–tofu soup). For most foods, THM uptake was diffusion limited and several hours were needed to approach steady-state levels. Swelling, hydrolysis and other physical and chemical changes in the food can significantly affect sorption. Screening level estimates for CHCl₃ exposures, based on experimental results and typical food consumption patterns, show that uptake via foods can dominate that due to direct tap water consumption, suggesting the importance of sorption and the need for further evaluation of THM intake due to foods.