scholarly journals Long-term Particulate Matter Modeling for Health Effects Studies in California – Part II: Concentrations and Sources of Ultrafine Organic Aerosols

Author(s):  
Jianlin Hu ◽  
Shantanu Jathar ◽  
Hongliang Zhang ◽  
Qi Ying ◽  
Shu-Hua Chen ◽  
...  

Abstract. Organic aerosol (OA) is a major constituent of ultrafine particulate matter (PM0.1). Recent epidemiological studies have identified associations between PM0.1 OA and premature mortality and low birth weight. In this study, the source-oriented UCD/CIT model was used to simulate the concentrations and sources of primary organic aerosols (POA) and secondary organic aerosols (SOA) in PM0.1 in California for a 9-year (2000–2008) modeling period with 4 km horizontal resolution to provide more insights about PM0.1 OA for health effects studies. As a related quality control, predicted monthly average concentrations of fine particulate matter (PM2.5) total organic carbon at six major urban sites had mean fractional bias of −0.31 to 0.19 and mean fractional errors of 0.4 to 0.59. The predicted ratio of PM2.5 SOA/OA was lower than estimates derived from chemical mass balance (CMB) calculations by a factor of 2 ~ 3, which suggests the potential effects of processes such as POA volatility, additional SOA formation mechanism, and missing sources. OA in PM0.1, the focus size fraction of this study, is dominated by POA. Wood smoke is found to be the single biggest source of PM0.1 OA in winter in California, while meat cooking, mobile emissions (gasoline and diesel engines), and other anthropogenic sources (mainly solvent usage and waste disposal) are the most important sources in summer. Biogenic emissions are predicted to be the largest PM0.1 SOA source, followed by mobile sources and other anthropogenic sources, but these rankings are sensitive to the SOA model used in the calculation. Air pollution control programs aiming to reduce the PM0.1 OA concentrations should consider controlling solvent usage, waste disposal, and mobile emissions in California, but these findings should be revisited after the latest science is incorporated into the SOA exposure calculations. The spatial distributions of SOA associated with different sources are not sensitive to the choice of SOA model, although the absolute amount of SOA can change significantly. Therefore, the spatial distributions of PM0.1 POA and SOA over the 9-year study period provide useful information for epidemiological studies to further investigate the associations with health outcomes.

2017 ◽  
Vol 17 (8) ◽  
pp. 5379-5391 ◽  
Author(s):  
Jianlin Hu ◽  
Shantanu Jathar ◽  
Hongliang Zhang ◽  
Qi Ying ◽  
Shu-Hua Chen ◽  
...  

Abstract. Organic aerosol (OA) is a major constituent of ultrafine particulate matter (PM0. 1). Recent epidemiological studies have identified associations between PM0. 1 OA and premature mortality and low birth weight. In this study, the source-oriented UCD/CIT model was used to simulate the concentrations and sources of primary organic aerosols (POA) and secondary organic aerosols (SOA) in PM0. 1 in California for a 9-year (2000–2008) modeling period with 4 km horizontal resolution to provide more insights about PM0. 1 OA for health effect studies. As a related quality control, predicted monthly average concentrations of fine particulate matter (PM2. 5) total organic carbon at six major urban sites had mean fractional bias of −0.31 to 0.19 and mean fractional errors of 0.4 to 0.59. The predicted ratio of PM2. 5 SOA ∕ OA was lower than estimates derived from chemical mass balance (CMB) calculations by a factor of 2–3, which suggests the potential effects of processes such as POA volatility, additional SOA formation mechanism, and missing sources. OA in PM0. 1, the focus size fraction of this study, is dominated by POA. Wood smoke is found to be the single biggest source of PM0. 1 OA in winter in California, while meat cooking, mobile emissions (gasoline and diesel engines), and other anthropogenic sources (mainly solvent usage and waste disposal) are the most important sources in summer. Biogenic emissions are predicted to be the largest PM0. 1 SOA source, followed by mobile sources and other anthropogenic sources, but these rankings are sensitive to the SOA model used in the calculation. Air pollution control programs aiming to reduce the PM0. 1 OA concentrations should consider controlling solvent usage, waste disposal, and mobile emissions in California, but these findings should be revisited after the latest science is incorporated into the SOA exposure calculations. The spatial distributions of SOA associated with different sources are not sensitive to the choice of SOA model, although the absolute amount of SOA can change significantly. Therefore, the spatial distributions of PM0. 1 POA and SOA over the 9-year study period provide useful information for epidemiological studies to further investigate the associations with health outcomes.


Author(s):  
Lu Yang ◽  
Hao Zhang ◽  
Xuan Zhang ◽  
Wanli Xing ◽  
Yan Wang ◽  
...  

Particulate matter (PM) is a major factor contributing to air quality deterioration that enters the atmosphere as a consequence of various natural and anthropogenic activities. In PM, polycyclic aromatic hydrocarbons (PAHs) represent a class of organic chemicals with at least two aromatic rings that are mainly directly emitted via the incomplete combustion of various organic materials. Numerous toxicological and epidemiological studies have proven adverse links between exposure to particulate matter-bound (PM-bound) PAHs and human health due to their carcinogenicity and mutagenicity. Among human exposure routes, inhalation is the main pathway regarding PM-bound PAHs in the atmosphere. Moreover, the concentrations of PM-bound PAHs differ among people, microenvironments and areas. Hence, understanding the behaviour of PM-bound PAHs in the atmosphere is crucial. However, because current techniques hardly monitor PAHs in real-time, timely feedback on PAHs including the characteristics of their concentration and composition, is not obtained via real-time analysis methods. Therefore, in this review, we summarize personal exposure, and indoor and outdoor PM-bound PAH concentrations for different participants, spaces, and cities worldwide in recent years. The main aims are to clarify the characteristics of PM-bound PAHs under different exposure conditions, in addition to the health effects and assessment methods of PAHs.


2019 ◽  
Author(s):  
Jun Zhou ◽  
Miriam Elser ◽  
Ru-Jin Huang ◽  
Manuel Krapf ◽  
Roman Fröhlich ◽  
...  

Abstract. Reactive oxygen species (ROS) are believed to contribute to the adverse health effects of aerosols. This may happen by inhaled particle-bound (exogenic) ROS (PB-ROS) or by ROS formed within the respiratory tract by certain aerosol components (endogenic ROS). We investigated the chemical composition of aerosols and their exogenic ROS content at the two contrasting locations Beijing (China) and Bern (Switzerland). We apportioned the ambient organic aerosol to different sources and attributed the observed PB-ROS to them. The oxygenated organic aerosol (OOA, a proxy for secondary organic aerosol, SOA) explained the highest fraction of the exogenic ROS concentration variance at both locations. We also characterized primary and secondary aerosol emissions generated from different biogenic and anthropogenic sources in smog chamber experiments. The exogenic PB-ROS content in the OOA from these emission sources was comparable to that in the ambient measurements. Our results imply that SOA from gaseous precursors of different anthropogenic emission sources is a crucial source of PB-ROS and should be additionally considered in toxicological and epidemiological studies in an adequate way besides primary emissions. The importance of PB-ROS may be connected to the seasonal trends in health effects of PM reported by epidemiological studies, with elevated incidences of adverse effects in warmer seasons, which are accompanied by more intense atmospheric oxidation processes.


Medicina ◽  
2012 ◽  
Vol 48 (9) ◽  
pp. 70
Author(s):  
Hans Orru ◽  
Aida Laukaitienė ◽  
Ingrida Zurlytė

Particulate matter in outdoor air has a significant impact on health. Small particles, composed of a variety of organic and inorganic compounds, are inhaled deep into the respiratory tract. The mechanisms and outcomes are manifold, resulting mainly in cardiopulmonary diseases. The current study aimed to quantify the health effects of particulate pollutants in Vilnius and Kaunas. Material and Methods. For risk estimation, the methodology of health impact assessment was employed. The exposure was defined as annual PM2.5 levels for long-term exposure effects and daily PM10 averages for short-term exposure effects. The baseline mortality/morbidity data were retrieved from health registers and exposure-response relationships from previous epidemiological studies. For health impact calculations, the WHO-developed tool AirQ was also applied. Results. The annual average concentration of PM2.5 was 11 μg/m3 in Vilnius and 17.5 μg/m3 in Kaunas. The exposure above the natural background corresponded annually to 263 (95% CI, 68– 464) and 338 (95% CI, 86–605) premature deaths in Vilnius and Kaunas. This resulted in 3438 (95% CI, 905–5952) and 3693 (95% CI, 983–6322) years of life lost and in an average decrease in life expectancy of 0.43 (95% CI, 0.11–0.74) and 0.69 (95% CI, 0.18–1.19) years, respectively. In addition, 143 (95% CI, 86–200) and 129 (95% CI, 78–179) respiratory and 297 (95% CI, 188–377) and 267 (95% CI, 169–338) cardiovascular hospitalizations per year could be expected in Vilnius and Kaunas, respectively. Conclusions. There is substantial exposure to particulate matter in the main Lithuanian cities, which causes considerable adverse health effects. Traffic and domestic heating are considered locally the most important contributing factors to the degradation of air quality.


Author(s):  
Alan da Silveira Fleck ◽  
Maximilien Debia ◽  
Patrick Eddy Ryan ◽  
Caroline Couture ◽  
Alison Traub ◽  
...  

Abstract Oxidative potential (OP) is a toxicologically relevant metric that integrates features like mass concentration and chemical composition of particulate matter (PM). Although it has been extensively explored as a metric for the characterization of environmental particles, this is still an underexplored application in the occupational field. This study aimed to estimate the OP of particles in two occupational settings from a construction trades school. This characterization also includes the comparison between activities, sampling strategies, and size fractions. Particulate mass concentrations (PM4-Personal, PM4-Area, and PM2.5-Area) and number concentrations were measured during three weeks of welding and construction/bricklaying activities. The OP was assessed by the ascorbate assay (OPAA) using a synthetic respiratory tract lining fluid (RTLF), while the oxidative burden (OBAA) was determined by multiplying the OPAA values with PM concentrations. Median (25th–75th percentiles) of PM mass and number concentrations were 900 (672–1730) µg m–3 and 128 000 (78 000–169 000) particles cm–3 for welding, and 432 (345–530) µg m–3 and 2800 (1700–4400) particles cm–3 for construction. Welding particles, especially from the first week of activities, were also associated with higher redox activity (OPAA: 3.3 (2.3–4.6) ρmol min–1 µg–1; OBAA: 1750 (893–4560) ρmol min–1 m–3) compared to the construction site (OPAA: 1.4 (1.0–1.8) ρmol min–1 µg–1; OBAA: 486 (341–695) ρmol min–1 m–3). The OPAA was independent of the sampling strategy or size fraction. However, driven by the higher PM concentrations, the OBAA from personal samples was higher compared to area samples in the welding shop, suggesting an influence of the sampling strategy on PM concentrations and OBAA. These results demonstrate that important levels of OPAA can be found in occupational settings, especially during welding activities. Furthermore, the OBAA found in both workplaces largely exceeded the levels found in environmental studies. Therefore, measures of OP and OB could be further explored as metrics for exposure assessment to occupational PM, as well as for associations with cardiorespiratory outcomes in future occupational epidemiological studies.


Author(s):  
N. A. S. Hamm

Epidemiological studies of the health effects of air pollution require estimation of individual exposure. It is not possible to obtain measurements at all relevant locations so it is necessary to predict at these space-time locations, either on the basis of dispersion from emission sources or by interpolating observations. This study used data obtained from a low-cost sensor network of 32 air quality monitoring stations in the Dutch city of Eindhoven, which make up the ILM (innovative air (quality) measurement system). These stations currently provide PM10 and PM2.5 (particulate matter less than 10 and 2.5 m in diameter), aggregated to hourly means. The data provide an unprecedented level of spatial and temporal detail for a city of this size. Despite these benefits the time series of measurements is characterized by missing values and noisy values. In this paper a space-time analysis is presented that is based on a dynamic model for the temporal component and a Gaussian process geostatistical for the spatial component. Spatial-temporal variability was dominated by the temporal component, although the spatial variability was also substantial. The model delivered accurate predictions for both isolated missing values and 24-hour periods of missing values (RMSE = 1.4 <i>&amp;mu;</i>g m<sup>&amp;minus;3</sup> and 1.8 <i>&amp;mu;</i>g m<sup>&amp;minus;3</sup> respectively). Outliers could be detected by comparison to the 95% prediction interval. The model shows promise for predicting missing values, outlier detection and for mapping to support health impact studies.


2006 ◽  
Vol 25 (10) ◽  
pp. 559-579 ◽  
Author(s):  
P E Schwarze ◽  
J Øvrevik ◽  
M Låg ◽  
M Refsnes ◽  
P Nafstad ◽  
...  

Identifying the ambient particulate matter (PM) fractions or constituents, critically involved in eliciting adverse health effects, is crucial to the implementation of more cost-efficient abatement strategies to improve air quality. This review focuses on the importance of different particle properties for PM-induced effects, and whether there is consistency in the results from epidemiological and experimental studies. An evident problem for such comparisons is that epidemiological and experimental data on the effects of specific components of ambient PM are limited. Despite this, some conclusions can be drawn. With respect to the importance of the PM size-fractions, experimental and epidemiological studies are somewhat conflicting, but there seems to be a certain consistency in that the coarse fraction (PM10-2.5) has an effect that should not be neglected. Better exposure characterization may improve the consistency between the results from experimental and epidemiological studies, in particular for ultrafine particles. Experimental data indicate that surface area is an important metric, but composition may play an even greater role in eliciting effects. The consistency between epidemiological and experimental findings for specific PM-components appears most convincing for metals, which seem to be important for the development of both pulmonary and cardiovascular disease. Metals may also be involved in PM-induced allergic sensitization, but the epidemiological evidence for this is scarce. Soluble organic compounds appear to be implicated in PM-induced allergy and cancer, but the data from epidemiological studies are insufficient for any conclusions. The present review suggests that there may be a need for improvements in research designs. In particular, there is a need for better exposure assessments in epidemiological investigations, whereas experimental data would benefit from an improved comparability of studies. Combined experimental and epidemiological investigations may also help answer some of the unresolved issues.


2021 ◽  
Author(s):  
Karuna Singh ◽  
Dhananjay Tripathi

This chapter provides an introduction to particulate matter by discussing various ways of categorisation, characterisation and their health effects. The natural and anthropogenic sources of atmospheric particulate matter are discussed. The chapter also introduces qualitatively some aerosol concepts, such as their chemical composition and size distribution. Some examples are provided to illustrate how particulate matter, despite being microscopic particles, can manifest themselves in the atmosphere. Finally, the various pathways by which particulate matter impacts the health system are reviewed along with their interactions to understand concept behind the PM-associated health effects.


Sign in / Sign up

Export Citation Format

Share Document