Luis Díaz-Robles

Particulate air pollution and health effects for cardiovascular and respiratory causes in Temuco, Chile: A wood-smoke-polluted urban area

Abstract Temuco is one of the most highly wood-smoke-polluted cities in the world. Its population in 2004 was 340,000 inhabitants with 1587 annual deaths, of which 24% were due to cardiovascular and 11% to respiratory causes. For hospital admissions, cardiovascular diseases represented 6% and respiratory diseases 13%. Emergency room visits for acute respiratory infections represented 28%. The objective of the study presented here was to determine the relationship between air pollution from particulate matter less than or equal to 10 µm in aerodynamic diameter (PM10; mostly PM2.5, or particulate matter <2.5 µm in aerodynamic diameter) and health effects measured as the daily number of deaths, hospital admissions, and emergency room visits for cardiovascular, respiratory, and acute respiratory infection (ARI) diseases. The Air Pollution Health Effects European Approach (APHEA2) protocol was followed, and a multivariate Poisson regression model was fitted, controlling for trend, seasonality, and confounders for Temuco during 1998–2006. The results show that PM10 had a significant association with daily mortality and morbidity, with the elderly (population >65 yr of age) being the group that presented the greatest risk. The relative risk for respiratory causes, with an increase of 100 µg/m3 of PM10, was 1.163 with a 95% confidence interval (CI) of 1.057–1.279 for mortality, 1.137 (CI 1.096–1.178) for hospital admissions, and 1.162 for ARI (CI 1.144–1.181). There is evidence in Temuco of positive relationships between ambient particulate levels and mortality, hospital admissions, and ARI for cardiovascular and respiratory diseases. These results are consistent with those of comparable studies in other similar cities where wood smoke is the most important air pollution problem.

Health risks caused by short term exposure to ultrafine particles generated by residential wood combustion: A case study of Temuco, Chile

Temuco is one of the most highly wood smoke polluted cities in Chile; however, there is scarce evidence of respiratory morbidity due to fine particulate matter. We aimed to estimate the relationship between daily concentration of ultrafine particles (UFP), with an aerodynamic diameter ≤ 0.1 μm, and outpatient visits for respiratory illness at medical care centers of Temuco, Chile, from August the 20th, 2009 to June the 30th, 2011. The Air Pollution Health Effects European Approach (APHEA2) protocol was followed, and a multivariate semi-parametric Poisson regression model was fitted with GAM techniques using R-Project statistical package; controlling for trend, seasonality, and confounders. The daily UFP were measured by a MOUDI NR-110 sampler. We found that results of the statistical analyses show significant associations between UFP and respiratory outpatient visits, with the elderly (population ≥ 65 years), being the group that presented the greatest risk. An interquartile increase of 4.73 μg/m(3) in UFP (lag 5 days) was associated with respiratory outpatient visits with a relative risk (RR) of 1.1458 [95% CI (1.0497-1.2507)] for the elderly. These results show novel findings regarding the relevance of daily UFP concentrations and health risk, especially for susceptible population in a wood smoke polluted city.

Obtaining polycyclic aromatic hydrocarbon concentration ratios and molecular markers for residential wood combustion: Temuco, a case study

It is known that residential wood combustion (RWC) is an important source of fine particle emissions. The purpose of this work was to characterize the chemical composition of the particulate matter present in the Temuco urban atmosphere during winter, specifically the polycyclic aromatic hydrocarbon (PAH) profile, because PAHs are considered to be among the key compounds in particulate matter toxicity. During the 2008 winter monitoring campaign, samples of particulate matter with aerodynamic diameters of ≤10 (PM10) and ≤2.5 (PM2.5) μm were taken on days with contamination episodes. Sixteen U.S. Environmental Protection Agency (EPA) PAH compounds were extracted with toluene and determined by gas chromatography–mass spectrometry (GC-MS). The results show that phenantrene was the predominant compound associated with particulate matter, at a concentration range between 300 and 600 ng m−3, 18 times higher than the second most abundant PAH compound. High-molecular-mass compounds such as dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3,c,d]pyrene were also found, but they were minorities in the set. It was recognized from the PAH concentration ratios of the Temuco atmospheric aerosol that the main contamination source was in fact residential wood combustion; although not all the concentration ratios evaluated match the reported reference values, probably due to the kind of biomass used, the characteristics of Chilean heating appliances and climate. Implications: The study results suggest that if molecular markers (MMs) and concentration ratios (CRs) are dependent on the type of firewood and combustion processes specific to each location, among others factors, then the values of these indicators could be applicable with caution between different areas, although not necessarily they must be totally in accord. Moreover, having representative values of MM and CR of each place, it will achieve a better estimation of the source importance and concentrate the monitoring and the control strategies. Regulatory organizations in each country can have more reliable information and optimize financial and human resources, enabling it to reduce air pollution and improve the health of population.

Seasonal distribution and modeling of diesel particulate matter in the Southeast US

The fine and ultra fine size of diesel particulate mater (DPM) are of great health concern and significantly contribute to the overall cancer risk. In addition, diesel particles may contribute a warming effect on the planets climate. The composition of these particles is composed principally of elemental carbon (EC) with adsorbed organic compounds, sulfate, nitrate, ammonia, metals, and other trace elements. The purpose of this study was to depict the seasonality and modeling of particulate matter in the Southeastern US produced by the diesel fueled sources (DFSs). The modeling results came from four one-month cases including March, June, September, and December to represent different seasons in 2003 by linking Models-3/CMAQ and SMOKE. The 1999 National Emissions Inventory Version 3 (NEI99) was used in this analysis for point, area, and non-road sources, whereas the National Mobile Inventory Model (NMIM) was used to create the on-road emissions. Three urban areas, Atlanta, Birmingham, and Nashville were selected to analyze the DPM emissions and concentrations. Even though the model performance was not very strong, it could be considered satisfactory to conduct seasonal distribution analysis for DPM. Important hourly DPM seasonality was observed in each city, of which higher values occurred at the morning traffic rush hours. The EC contributions of primary DPM were similar for all three sites (approximately 74%). The results showed that there is no significant daily seasonality of DPM contribution to PM(2.5) for any of these three cities in 2003. The annual DPM contribution to total PM(2.5) for Atlanta, Nashville, and Birmingham were 3.7%, 2.5%, and 2.2%, respectively.

Application of a New Methodology for Determining Polycyclic Aromatic Hydrocarbons (Pahs) in Atmospheric Aerosols Using Different Filter Configurations, Puf and Xad-Denuder

Scientia Chromatographica 2016; 8(3) 189 Abstract Recognizing that the Polycyclic Aromatic Hydrocarbons (PAHs) are semi volatile organic compounds (SVOCs), are distributed between the gas phases (GP) and the atmospheric particulate matter (PM), and have a recognized toxicity, it is increasingly important that their analysis was as reliable as possible. For this purpose, the combination of different kinds of membrane filters has been used frequently, as well as polyurethane foam filters (PUF), to sample the gaseous phase. However, this technique is unreliable for determining the distribution between the phases, due mainly to different types of sampling artifacts. Considering this issue, a new methodology for determining the PAHs phase distribution is proposed. This technique involves the utilization of the combination of parallel cartridges, one equipped with membrane filter and PUF (F+PUF) and other with F+PUF+ XAD Denuder (XAD-D). This methodology was proved in a PAHs monitoring campaign in the urban air of Temuco, Chile, in winter season and the obtained results indicate using the combination of cartridge (F+PUF) and (F+PUF+ XAD), we are reducing the effect of sampling artifacts on the determination of the atmospheric concentration of PAHs.