A method to derive the relationship between the annual and short-term air quality limits—Analysis using the WHO Air Quality Guidelines for health protection

The World Health Organization (WHO) Air Quality Guidelines (AQG) were launched in 2006, but gaps remain in evidence on health impacts and relationships between short-term and annual AQG needed for health protection. We tested whether relationships between WHO short-term and annual AQG for particulates (PM₁₀ and PM_2.5) and nitrogen dioxide (NO₂) are concordant worldwide and derived the annual limits for sulfur dioxide (SO₂) and ozone (O₃) based on the short-term AQG. We obtained air pollutant data over seven years (2004–2010) in seven cities from Asia-Pacific, North America and Europe. Based on probability distribution concept using maximum as the short-term limit and arithmetic mean as the annual limit, we developed a new method to derive limit value one from another in each paired limits for each pollutant with capability to account for allowable exceedances. We averaged the limit derived each year for each city, then used meta-analysis to pool the limit values in all cities. Pooled mean short-term limit for NO₂ (140.5 μg/m³ [130.6–150.4]) was significantly lower than the WHO AQG of 200 μg/m³ while for PM₁₀ (46.4 μg/m³ [95CI:42.1–50.7]) and PM_2.5 (28.6 μg/m³ [24.5–32.6]) were not significantly different from the WHO AQG of 50 and 25 μg/m³ respectively. Pooled mean annual limits for SO₂ and O₃ were 4.6 μg/m³ [3.7–5.5] and 27.0 μg/m³ [21.7–32.2] respectively. Results were robust in various sensitivity analyses. The distribution relationships between the current WHO short-term and annual AQG are supported by empirical data from seven cities for PM₁₀ and PM_2.5, but not for NO₂. The short-term AQG for NO₂ should be lowered for concordance with the selected annual AQG for health protection.     

Ambient air pollution and children's lung function in China

ObjectiveTo describe the correlations between ambient air pollutants (TSP, SO₂, NO_x) and the level of children's lung function (FVC, FEV₁, MMEF) in China.MethodsWe collected the research articles on ambient air pollution and children's lung function published from 1985 to 2006 and selected 11 articles finally according to the following criteria: (1) Children between the age of 7 and 15 as objects; (2) Local air quality monitoring results were reported; (3) Strict quality control was taken when testing children's lung function; (4) The results were expressed by the average of measured value. Then we analyzed the correlation relationship between the level of ambient air pollutants and children's lung function and compared the effects of ambient air pollutants on children's lung function of boy and girl.ResultsThe selected articles included the results of 7 cities in China. Among them, the results of 6 cities' studies revealed that the levels of children's lung function were significantly lower in the areas with heavy ambient air pollution than those in the areas with light ambient air pollution. According to the articles, the average levels of TSP were at the range of 0.084 mg/m³–0.835 mg/m³, SO₂ were 0.013 mg/m³–0.929 mg/m³, NO_x were 0.044 mg/m³–0.229 mg/m³. Correlation analysis showed significant negative correlation between the levels of TSP and SO₂ and children's FVC and FEV₁, as well as the levels of NO_x and children's MMEF. The correlation coefficient was ? 0.797 (t = ? 4.384, P = 0.001) between TSP and FVC, ? 0.693 (t = ? 4.190, P < 0.001) between Ln (SO₂) and FVC, ? 0.886 (t = ? 5.392, P = 0.001) and ? 0.685 (t = ? 4.101, P = 0.001) between FEV₁ and TSP and Ln (SO₂), and ? 0.973 (t = ? 5.993, P = 0.027) between NO_xNO_x and MMEF, respectively. The results also suggested that the decreases of lung function for girl with the increasing of ambient air pollution were significantly greater for boy.ConclusionThe levels of ambient air TSP and SO₂ correlated with the damage of the big airway function of children, while NO_xNO_x affected the small airway function chiefly. Furthermore, lung function of girl was more susceptible to ambient air pollutants than boy.     

Comparison of indoor and outdoor air quality at two staff quarters in Hong Kong

The indoor and outdoor air quality of two staff quarters of Hong Kong Polytechnic University at Tsim Sha Tsui East (TSTE) and Shatin (ST) were investigated. The air sampling was carried out in winter for about two months starting from January to February of 1996. Fifteen flats from each staff quarter were randomly selected for indoor/outdoor air pollutant measurements. The pollutants measured were NO_x, NO, NO₂, SO₂, CO, and O₃. The variations of pollutant concentrations between indoor and outdoor air were investigated on weekday mornings, weekday evenings, weekend mornings, and weekend evenings. All indoor/outdoor pollutant concentrations measured did not exceed the ASHRAE/NAAQS standard. The carbon monoxide concentrations indoors were systemically higher than those outdoors at the TSTE and the ST quarters, both on weekdays and Sunday, which indicates there are CO sources indoors. Except for CO, the indoor levels of other pollutants (NO_x, NO, NO₂, SO₂, and O₃) are lower than those outdoors. There was a significant correlation (P < 0.05) between indoor and outdoor concentrations for SO₂ and O₃ at both the TSTE and the ST quarters. Except for O₃, the mean concentrations of all the pollutants in the TSTE quarters, both indoor and outdoor, were higher than that of the ST quarters in all sampling periods. All indoor and outdoor O₃ levels were lower at the TSTE quarters than those at the ST quarters. The O₃ ratios of TSTE/ST were 0.72 outdoor and 0.79 indoor. This can be explained by the NO titration reaction through NO conversion to NO₂.     

Population exposure to airborne thorium at the high natural radiation areas in India

High natural radiation areas in the coastal and peninsular India were studied for airborne thorium and resultant population exposure due to inhalation. Four locations covering three states viz., Ayiramthengu and Neendakara in Kerala, Kudiraimozhi in Tamil Nadu and Bhimilipatnam in Andhra Pradesh were investigated. External gamma radiation fields 1 m above the monazite ore bodies ranged from 200 to 3000 nGy h^-1. Soil samples showed ²³²Th specific activity varying from 0·1 to 1·5 Bq g^-1 with surface alpha activity in the range of 1·0–12·5 Bq cm^-2. Suspended particulates in the samples ranged from 60–140 μg m^-3 with ²³²Th showing a wider variation of <0·03–0·3 mBq m^-3. There was poor correlation between suspended particulates and long-lived alpha airborne activity . The resuspension factors for ²³²Th were in the range of 1·5×10^-8–7·9×10^-7 cm^-1. Higher resuspension was correlated with dry sand dunes. The upper limits for Committed Effective Dose (CED) due to inhalation of airborne ²³²Th at the respective high natural radiation areas were estimated to range from 50±30 to 300±130 μSv (5–30 mrem) per year per adult member of public assuming an activity median aerodynamic diameter of 1 μm for the airborne particulates.     

Association between long-term exposure to air pollution and mortality in France: A 25-year follow-up study

IntroductionLong-term exposure to air pollution (AP) has been shown to have an impact on mortality in numerous countries, but since 2005 no data exists for France.ObjectivesWe analyzed the association between long-term exposure to air pollution and mortality at the individual level in a large French cohort followed from 1989 to 2013.MethodsThe study sample consisted of 20,327 adults working at the French national electricity and gas company EDF-GDF. Annual exposure to PM₁₀, PM_10–2.5, PM_2.5, NO₂, O₃, SO₂, and benzene was assessed for the place of residence of participants using a chemistry-transport model and taking residential history into account. Hazard ratios were estimated using a Cox proportional-hazards regression model, adjusted for selected individual and contextual risk factors. Hazard ratios were computed for an interquartile range (IQR) increase in air pollutant concentrations.ResultsThe cohort recorded 1967 non-accidental deaths. Long-term exposures to baseline PM_2.5, PM_10-25, NO₂ and benzene were associated with an increase in non-accidental mortality (Hazard Ratio, HR = 1.09; 95% CI: 0.99, 1.20 per 5.9 μg/m³, PM_10-25; HR = 1.09;95% CI: 1.04, 1.15 per 2.2 μg/m³, NO₂: HR = 1.14; 95% CI: 0.99, 1.31 per 19.3 μg/m³ and benzene: HR = 1.10; 95% CI: 1.00, 1.22 per 1.7 μg/m³).The strongest association was found for PM₁₀: HR = 1.14; 95% CI: 1.05, 1.25 per 7.8 μg/m³. PM₁₀, PM_10-25 and SO₂ were associated with non-accidental mortality when using time varying exposure. No significant associations were observed between air pollution and cardiovascular and respiratory mortality.ConclusionLong-term exposure to fine particles, nitrogen dioxide, sulfur dioxide and benzene is associated with an increased risk of non-accidental mortality in France. Our results strengthen existing evidence that outdoor air pollution is a significant environmental risk factor for mortality. Due to the limited sample size and the nature of our study (occupational), further investigations are needed in France with a larger representative population sample.     

Air pollutant exposure and preterm and term small-for-gestational-age births in Detroit,Michigan: Long-term trends and associations

Studies in a number of countries have reported associations between exposure to ambient air pollutants and adverse birth outcomes, including low birth weight, preterm birth (PTB) and, less commonly, small for gestational age (SGA). Despite their growing number, the available studies have significant limitations, e.g., incomplete control of temporal trends in exposure, modest sample sizes, and a lack of information regarding individual risk factors such as smoking. No study has yet examined large numbers of susceptible individuals.We investigated the association between ambient air pollutant concentrations and term SGA and PTB outcomes among 164,905 singleton births in Detroit, Michigan occurring between 1990 and 2001. SO₂, CO, NO₂, O₃ and PM₁₀ exposures were used in single and multiple pollutant logistic regression models to estimate odds ratios (OR) for these outcomes, adjusted for the infant's sex and gestational age, the mother's race, age group, education level, smoking status and prenatal care, birth season, site of residence, and long-term exposure trends.Term SGA was associated with CO levels exceeding 0.75 ppm (OR = 1.14, 95% confidence interval = 1.02–1.27) and NO₂ exceeding 6.8 ppb (1.11, 1.03–1.21) exposures in the first month, and with PM₁₀ exceeding 35 μg/m³ (1.22, 1.03–1.46) and O₃ (1.11, 1.02–1.20) exposure in the third trimester. PTB was associated with SO₂ (1.07, 1.01–1.14) exposure in the last month, and with (hourly) O₃ exceeding 92 ppb (1.08, 1.02–1.14) exposure in the first month.Exposure to several air pollutants at modest concentrations was associated with adverse birth outcomes. This study, which included a large Black population, suggests the importance of the early period of pregnancy for associations between term SGA with CO and NO₂, and between O₃ with PTB; and the late pregnancy period for associations between term SGA and O₃ and PM₁₀, and between SO₂ with PTB. It also highlights the importance of accounting for individual risk factors such as maternal smoking, maternal race, and long-term trends in air pollutant levels and adverse birth outcomes in evaluating relationships between pollutant exposures and adverse birth outcomes.     

Chemical characteristics of precipitation and wet deposition of major ions in Liaozhong County of Liaoning Province,Northeast China

The chemical characteristics of precipitation were analyzed based on the chemical composition of principal ionic within acid rain（from February 2007 to January 2008）of Liaozhong Meteorological Station located in Malong Village in Liaozhong County of Northeast China,meteorological conditions on the corresponding period ground,and variation of several air pollutants concentration.The results indicated that:（1）The precipitation average pH value of all samples was4.76;the frequency of acid rain during the observation period was 70.7%;the frequency was 82.8%in summer and autumn.（2）In the chemical composition of precipitation,the primary anions were SO₄^2-and NO₃^-;the primary cations were NH₄⁺and Ca²⁺.（3）All concentration of anions was higher in summer and winter,but relatively low in spring and autumn.This showed that the relationship between regional rainfall acidification and pollution was not significant.（4）Rainwater acidity and nearly floor gaseous pollution concentration were different from each other,and pH and NO_x,CO,NO₂ and O₃concentrations showed significant negative correlation,but was not obvious with SO₂ concentration.However,the pH and alkaline pollutants,such as particulate,was positively correlative.     

The emission inventory of atmospheric industrial pollution sources of the five cities in Zhejiang Province

The amount of several air pollutants emitted in some cities including Hangzhou, Ningbo, Huzhou, Shaoxing and Jiaxing of Zhejiang Province is based on pollution source census data of Zhejiang Province in 2010. This paper focused on the release of air pollutants such as NO_x, SO₂, CO, PM2.5, PM10 and VOC, and calculated the total amount of those air pollutants. It analyzed air pollutant emission factors and found that the electricity and heat production industry released the largest amount of pollutants.     

Inflammatory markers in relation to long-term air pollution

Long-term exposure to ambient air pollution can lead to chronic health effects such as cancer, cardiovascular and respiratory disease. Systemic inflammation has been hypothesized as a putative biological mechanism contributing to these adverse health effects. We evaluated the effect of long-term exposure to air pollution on blood markers of systemic inflammation.We measured a panel of 28 inflammatory markers in peripheral blood samples from 587 individuals that were biobanked as part of a prospective study. Participants were from Varese and Turin (Italy) and Umea (Sweden). Long-term air pollution estimates of nitrogen oxides (NO_x) were available from the European Study of Cohorts for Air Pollution Effects (ESCAPE). Linear mixed models adjusted for potential confounders were applied to assess the association between NO_x and the markers of inflammation.Long-term exposure to NO_x was associated with decreased levels of interleukin (IL)-2, IL-8, IL-10 and tumor necrosis factor-α in Italy, but not in Sweden. NO_x exposure levels were considerably lower in Sweden than in Italy (Sweden: median (5th, 95th percentiles) 6.65 μg/m³ (4.8, 19.7); Italy: median (5th, 95th percentiles) 94.2 μg/m³ (7.8, 124.5)). Combining data from Italy and Sweden we only observed a significant association between long-term exposure to NO_x and decreased levels of circulating IL-8.We observed some indication for perturbations in the inflammatory markers due to long-term exposure to NO_x. Effects were stronger in Italy than in Sweden, potentially reflecting the difference in air pollution levels between the two cohorts.     

Activities of Po and Pb in the water column at Kuala Selangor, Malaysia

Natural radionuclides, such as ²¹⁰Po and ²¹⁰Pb were measured in the water samples collected from six stations at Kuala Selangor, Malaysia. Results for ²¹⁰Po and ²¹⁰Pb in dissolved and particulate phases have showed the difference in distribution and chemical behavior. The fluctuation activities of ²¹⁰Po and ²¹⁰Pb depend on wave action, geology and degree of fresh water input occurring at study areas and probably due to different sampling dates. The distribution coefficient, K_d, values of ²¹⁰Po and ²¹⁰Pb ranged from 2.0 × 10³ l g⁻¹ to 265.15 × 10⁵ l g⁻¹, and from 3.0 × 10³ l g⁻¹ to 558.16 × 10⁵ l g⁻¹, respectively. High K_d values of ²¹⁰Po and ²¹⁰Pb indicated that a strong adsorption of ²¹⁰Po and ²¹⁰Pb onto suspended particles, and the sinking of both nuclides on the seabed at study locations were controlled by the characteristics of suspended particles.     

Effect of cigarette smoking on residential NO2 levels

Two studies evaluating the levels and sources of nitrogen dioxide in approximately 90 employee homes in the Richmond area with continuous sampling during the weeks of August 5, 1980, and February 9, 1981, were performed using samplers in the living room, bedroom, kitchen, and outdoors. Additional data were collected concerning appliance usage, heating/cooling plant, ventilation and cigarette smoking. Results were analyzed using BMDP routines. The largest contributor to NO₂ concentration was found to be gas-fired kitchen appliances. The mean kitchen level for homes with gas appliances during the winter study was 188 μg/m³. Excluding participants with gas kitchens, incremental influence due to cigarette smoking was detected. The 7-day, 3-room average level of NO₂ in the homes of nonsmokers and smokers without gas-fired appliances was 12 and 15 μg/m³, respectively, in the summer. The corresponding winter values were 19 and 22 μg/m³. Furthermore, the individual levels of NO₂ in the homes of smokers were generally below both the adjacent outdoor level and the National Ambient Air Quality Standard limit for annual exposure.     

Introduction to and experimental conditions during the first year of the GMR chronic inhalation studies of diesel exhaust

A chronic exposure study was initiated to determine the effects of diesel exhaust on the health of experimental animals. For this purpose, test atmospheres of clean air (control) or freshly diluted diesel exhaust at concentrations of 250, 750, and 1500 μg/m³ were supplied to four 12.6 m³ inhalation chambers which housed rats and guinea pigs. Diesel aerosol size and concentration, as well as chamber temperature and relative humidity, were continually monitored and controlled to maintain the exposure dose levels and an environment of 22±2°C and 50%±20% relative humidity. The concentrations of CO and NO_x were found to be 5.8±1.0 mg/m³ and 7.9±1.0 mg/m³ above ambient in the chamber containing 1500 μg/m³ of particulate. Animals were supplied from the chambers, on a random basis, for both intramural and extramural studies throughout the exposure period. The experiment ran uninterrupted for over twelve months with mean diesel particle mass concentrations within 2% of the target values.     

Associations between short-term exposure to nitrogen dioxide and mortality in 17 Chinese cities: The China Air Pollution and Health Effects Study (CAPES)

Few multi-city studies in Asian developing countries have examined the acute health effects of ambient nitrogen dioxide (NO₂). In the China Air Pollution and Health Effects Study (CAPES), we investigated the short-term association between NO₂ and mortality in 17 Chinese cities. We applied two-stage Bayesian hierarchical models to obtain city-specific and national average estimates for NO₂. In each city, we used Poisson regression models incorporating natural spline smoothing functions to adjust for long-term and seasonal trend of mortality, as well as other time-varying covariates. We examined the associations by age, gender and education status. We combined the individual-city estimates of the concentration–response curves to get an overall NO₂–mortality association in China. The averaged daily concentrations of NO₂ in the 17 Chinese cities ranged from 26 μg/m³ to 67 μg/m³. In the combined analysis, a 10-μg/m³ increase in two-day moving averaged NO₂ was associated with a 1.63% [95% posterior interval (PI), 1.09 to 2.17], 1.80% (95% PI, 1.00 to 2.59) and 2.52% (95% PI, 1.44 to 3.59) increase of total, cardiovascular, and respiratory mortality, respectively. These associations remained significant after adjustment for ambient particles or sulfur dioxide (SO₂). Older people appeared to be more vulnerable to NO₂ exposure. The combined concentration–response curves indicated a linear association. Conclusively, this largest epidemiologic study of NO₂ in Asian developing countries to date suggests that short-term exposure to NO₂ is associated with increased mortality risk.     

Annual and diurnal variations of gaseous and particulate pollutants in 31 provincial capital cities based on in situ air quality monitoring data from China National Environmental Monitoring Center

Long-term air quality data with high temporal and spatial resolutions are needed to understand some important processes affecting the air quality and corresponding environmental and health effects. The annual and diurnal variations of each criteria pollutant including PM_2.5 and PM₁₀ (particulate matter with aerodynamic diameter less than 2.5 μm and 10 μm, respectively), CO (carbon monoxide), NO₂ (nitrogen dioxide), SO₂ (sulfur dioxide) and O₃ (ozone) in 31 provincial capital cities between April 2014 and March 2015 were investigated by cluster analysis to evaluate current air pollution situations in China, and the cities were classified as severely, moderately, and slightly polluted cities according to the variations. The concentrations of air pollutants in winter months were significantly higher than those in other months with the exception of O₃, and the cities with the highest CO and SO₂ concentrations were located in northern China. The annual variation of PM_2.5 concentrations in northern cities was bimodal with comparable peaks in October 2014 and January 2015, while that in southern China was unobvious with slightly high PM_2.5 concentrations in winter months. The concentrations of particulate matter and trace gases from primary emissions (SO₂ and CO) and NO₂ were low in the afternoon (~ 16:00), while diurnal variation of O₃ concentrations was opposite to that of other pollutants with the highest values in the afternoon. The most polluted cities were mainly located in North China Plain, while slightly polluted cities mostly focus on southern China and the cities with high altitude such as Lasa. This study provides a basis for the formulation of future urban air pollution control measures in China.     

The global carbon cycle and possible disturbances due to man's interventions

Global atmospheric CO₂ concentration has increased since the beginning of reliable monitoring in 1958 at a mean rate of about 0.9 ppm CO₂/yr. Now, atmospheric CO₂ concentration is at 330 ppm. From about 1860 up to 1974, man's intervention in the global carbon cycle caused a likely increase of 76.6 × 10¹⁵ gC, corresponding to 36 ppm CO₂ in the atmosphere, if a preindustrial content of 294 ppm CO₂ or 625.3 × 10¹⁵ g C is adopted to be valid. A further rise of atmospheric CO₂ seems to be inevitable and probably will be responsible for a climatic warming in the next several decades; therefore, a global examination of carbon reservoirs and carbon fluxes has been undertaken to determine their storage capacity for excess carbon which orginated mainly from burning fossil fuels and from land clearing. During 1860–1974 about 136 × 10¹⁵ g C have ben emitted into the atmosphere by fossil fuel combustion and cement production. At present, the emission rate is about 5 × 10¹⁵ g C/yr. The worldwide examination of carbon release, primarily by deforestation and soil cultivation since 1860, is estimated to be about 120 × 10¹⁵ g C. The net transfer of carbon to the atmosphere owing to man's interference with the biosphere is now believed to be about 2.4 × 10¹⁵ g C/yr. An oceanic uptake of roughly 179 × 10¹⁵ g C since 1860 is open to discussion. According to the chemical buffering of sea surface water only about 35.5 × 10¹⁵ g C could have been absorbed. It is argued, however, that oceanic circulations might have been more effective in removing atmospheric excess carbon of anthropogenic origin.     

Sidestream tobacco smoke constituents in indoor air modelled in an experimental chamber— Polycyclic aromatic hydrocarbons

Exposure to sidestream tobacco smoke is concerned with constituents in suspension in the indoor atmosphere. The natural dissipation of sidestream tobacco smoke has been investigated in a static atmosphere in a 10 m³ experimental chamber, and the rate of dissipation is expressed as T_0.5, the half-life of residence in the air. Respective T_0.5 of smoke components are calculated from the various sample data points, assuming a kinetic equation of the first-order process. Sidestream smoke has been generated by a smoking machine according to the Coresta standard protocol and then left to age over an 8-hour period, with subsequent sampling at defined time intervals. The experiments have been repeated over five days, and eight data point samples are obtained for each experiment. Besides nicotine, CO, and smoke particulate matter, interest has been focused on polycyclic aromatic hydrocarbons (PAH). The initial concentrations, C₀ for smoke particulate matter and nicotine (gas and particulate phases) are found to be 13.8 mg and 92 μg per cigarette per cubic meter, with T_0.5 being 2.6 and 2.1 hours, respectively. Low molecular-weight PAH have T_0.5 up to 20 hours, explainable only by their high concentrations in the gas phase, while the 3- to 7-ring PAH have T_0.5 of about 2 hours. The contribution of CO to ambient concentration is 91 mg per cigarette per cubic meter. The data can be useful in mathematical modellization studies regarding ventilation or exposure to sidestream smoke.     

Two-year follow-up study of nonregulatory recommendations for better air quality in indoor ice arenas

A standardized questionnaire was used in a two-year follow-up study to test the effectiveness of non-regulatory recommendations to improve indoor air quality of 103 ice arenas in Finland. In addition, the performance of a state-of-the-art emission control technology (ECT) on propane-fueled resurfacers was evaluated by measuring the one-week average nitrogen dioxide (NO₂) concentration in a small sample of arenas. The number of retrofitted ECT on propane-fueled resurfacers increased from 6 to 37 (8% to 37% of ice arenas) and the number of electric resurfacers from 7 to 9 (both 9% of arenas) in 1994–1996. At the same time, the prevalence of inadequate ventilation increased among the most susceptible small arenas (volume <30 000 m³) from 11 (31%) to 19 (38%). Combustion-powered resurfacers (88%) and inadequate ventilation (24%) were prevalent also among the 17 new arenas built in 1994–1996. ECT resurfacers significantly decreased the mean indoor NO₂ concentration of eleven arenas from 650 μg/m³ to 147 μg/m³. Thus, retrofitting resurfacers with ECT seems to be a feasible mitigation option to improve indoor air quality in ice arenas, but the ultimate solution is an electric ice resurfacer. Non-regulatory recommendations seem to be partially effective in abatement against the air quality problems, but additional regulatory measures are needed for full compliance in all arenas.     

Associations of gestational and early life exposures to ambient air pollution with childhood respiratory diseases in Shanghai,China: A retrospective cohort study

BackgroundAssociations of ambient air pollutants with respiratory health are inconsistent.ObjectivesWe analyzed the associations of gestational and early life exposures to air pollutants with doctor-diagnosed asthma, allergic rhinitis, and pneumonia in children.MethodsWe selected 3358 preschool children who did not alter residences after birth from a cross-sectional study in 2011–2012 in Shanghai, China. Parents reported children's respiratory health history, home environment, and family lifestyle behaviors. We collected daily concentrations of sulphur dioxide (SO₂), nitrogen dioxide (NO₂), and particulate matter with an aerodynamic diameter ≤ 10 μm (PM₁₀) during the child's total lifetime (2006–2012) for each district where the children lived. We analyzed the associations using logistic regression models.ResultsAfter adjusting for covariates and the other studied pollutants, we found that exposure to NO₂ (increment of 20 μg/m³) during the first year of life was significantly associated with asthma [odds ratio (OR) = 1.77; 95% confidence interval (CI): 1.29–2.43] and allergic rhinitis (OR = 1.67; 95% CI: 1.07–2.61). Exposure to NO₂ during gestation, the first two and three years, and over total lifetimewas all consistently associated with increased odds of allergic rhinitis. Quartiles of NO₂ concentration during different exposure periods showed a slight dose–response relationship with the studied diseases. These diseases had significant associations with pollutant mixtures that included NO₂, but had no significant association with exposures to SO₂ and PM₁₀ individually or in mixtures.ConclusionsGestational and early life exposures to ambient NO₂ are risk factors for childhood respiratory diseases.     

Concentrations and determinants of outdoor, indoor and personal nitrogen dioxide in pregnant women from two Spanish birth cohorts

Determinants of outdoor, indoor and personal concentrations of nitrogen dioxide (NO₂) were assessed in a subset of pregnant women of the Spanish INMA (Environment and Childhood) Study. Home indoor and outdoor NO₂ concentrations were measured during 48 h with passive samplers for 50 and 58 women from the INMA cohorts of Valencia and Sabadell, respectively. Women from Sabadell also carried personal NO₂ samplers during the same period. Data on time–activity patterns, socio-economic characteristics, and environmental exposures were obtained through questionnaires. Multiple linear regression models were developed to predict NO₂ levels.In Valencia, median outdoor NO₂ levels (42 µg/m³) were higher than median indoor levels (36 µg/m³). In Sabadell, personal NO₂ showed the highest median levels (40 µg/m³), followed by indoor (32 µg/m³) and outdoor (29 µg/m³) levels. Personal exposure to NO₂ correlated best with the indoor NO₂ levels. Temporal and traffic-related variables were significant predictors for outdoor NO₂ levels. Thirty-two percent of the indoor NO₂ variability in the two cohorts was explained by outdoor NO₂ levels and the use of the gas appliances. The model for personal exposure accounted for 59% of the variance in NO₂ levels in Sabadell with four predictor variables (outdoor and indoor NO₂ levels, time spent in outdoor environments and time exposed to a gas cooker). No significant association was found between personal or indoor NO₂ levels and exposure to environmental tobacco smoke (ETS) at home.Personal NO₂ levels were found to be strongly influenced by indoor NO₂ concentrations. The study supports the use of time–activity patterns along with indoor measurements to predict personal exposure to traffic-related air pollution.     

Short-term effects of air pollution on respiratory morbidity at Rio de Janeiro — PART I: Air Pollution Assessment

Exposure to air pollution has been related with the most varied adverse health outcomes. This study aims to assess the impact of air pollution on the emergency hospitalization 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 I aims to: i) evaluate the concentrations of PM₁₀, SO₂ and CO at two sites in Rio de Janeiro and compare them; ii) analyse the concentrations observed according to the national and international standards; and iii) analyse the air pollutants behaviour, namely, annually, seasonally, daily and considering weekdays/weekends variations. The pollutant concentrations were measured at two different sites in Rio de Janeiro and the analysis was performed for the period between September 2000 and December 2005. Results showed that PM₁₀ concentrations in Rio de Janeiro exceeded the daily and annual standards imposed by the European Union, the Brazilian legislation and WHO guidelines. Regarding SO₂ and CO, concentrations were, generally, below both European and Brazilian standards. Nevertheless, considering WHO guidelines, SO₂ threshold for daily concentrations (20 μg m^− 3) was exceeded around 150 times. Behaviour assessment showed that the influence of traffic is a major factor affecting the air pollution in Rio de Janeiro.Considering the results achieved and the proven health effects of air pollution, strategies should be defined for its reduction, particularly concerning particulate matter, and consequently contribute to the protection of public health.