Source apportionment of size-segregated atmospheric particles and the influence of particles deposition in the human respiratory tract in rural and urban locations of north-east India.

Aerosol samples were collected using eight stage non-viable Andersen cascade impactor at three urban and two rural sites in north-east India during 2018 covering three seasons i.e., winter, summer and monsoon. The size-segregated samples collected in the selected locations were carefully analysed in terms of deposition in human respiratory tract using inhalation and deposition curves. Seasonal variation of fractional deposition of particulate matter (PM) in human respiratory tract was observed. For example, during winter, in one of the urban sites i.e., S3 (0.61) the maximum deposition was in Pulmonary (P) region, while in the case of other sites, the maximum deposition was in Nasopharyngeal (NOPL) region. Regional deposition in P was high in S1 and S3 when compared with other sites. Vehicular emissions was dominant in both S1 and S3 in P, while biomass burning being dominant in S3 which could be the reason for maximum deposition in P. Positive matrix factorization (PMF) revealed five to eight factors at each individual site in NOPL, tracheobronchial (TB) and P regions: biomass burning (accounting for 7-32% of PM), coal combustion (14-27%), construction dust (9-25%), dust emissions (17-28%), industrial emissions (12-26%), oil refinery (18%), secondary aerosols (17-33%) and vehicular emissions (12-39%). Dominant sources in urban and rural areas were vehicular emissions and dust emissions, respectively. Therefore, the present study highlights the importance of analyzing source apportionment of PM at ultrafine scale and forms a basis upon which the future air quality studies and mitigation strategies can be formulated in this region.

Source apportionment of organic pollutants in fine and coarse atmospheric particles in Doha, Qatar.

In this study, we investigated the sources of organic pollutants associated with fine (PM2.5) and coarse (PM2.5-10) atmospheric particulate matter in Doha, Qatar based on an eight-month sampling campaign conducted from May to December 2015. Multiple organic compound tracers including 36 PAH members, 25 n-alkane homologs, 17 hopanes, and 12 steranes were used for organic aerosols source apportionment. Source apportionment based on specific molecular markers, molecular diagnostic ratios/indices, and positive matrix factorization (PMF) modeling showed that similar sources are responsible for both fine- and coarse-particle organic pollutants. PMF analysis showed that biogenic aerosols, fugitive dust emissions, gasoline engine emissions, diesel engine emissions, and heavy oil combustion were the five main pollution sources of organic aerosols, which agreed well with the results from the diagnostic ratios analysis. The conditional bivariate probability functions (CPF) and potential source contribution function (PSCF) indicated that both regional (i.e., mixed biogenic/secondary particles and oil refinery/shipping emissions) and local sources contributed to airborne organic aerosol concentrations observed at the site, depending on the wind speed and direction. It appears that the relatively high levels of organic pollutants were contributed by local anthropogenic sources, such as fossil fuel combustion, vehicular emissions, and fugitive dust emissions. The high levels of local contributions indicated that there might be great opportunities for Qatar to considerably reduce emissions so that population exposures to carbonaceous aerosols and the public health risks associated with air pollution can be minimized. Implications: Multiple organic tracers and various source apportionment techniques have been used for convincing source apportionment. It was found that both long-range and local sources have a significant impact on atmospheric carbonaceous particles in the area, depending on the wind conditions. Relatively high levels of organic pollutants attributed to local anthropogenic sources indicate that there are great opportunities for Qatar to establish and implement more efficient pollution control measures and policies. Regional sources such as petroleum refineries and shipping-vessels emissions in the Gulf region should also be regulated and managed through regional cooperation to improve the air quality in the region.

Characterization of PM10 and Impact on Human Health During the Annual Festival of Lights (Diwali).

BACKGROUND: Diwali is a Hindu holiday observed each autumn in India, where it is known as the 'celebration of lights'. Burning of fireworks on this day leads to air and noise pollution, causing adverse effects to human health. OBJECTIVES: To monitor and analyze air quality and noise levels in a residential college campus in northeast India over Diwali 2015. METHODS: Components of PM10, including metals (cadmium (Cd), cobalt (Co), iron (Fe), zinc (Zn) and nickel (Ni)), ions (calcium (Ca2+), ammonium (NH4 +), sodium (Na+), potassium (K+), chloride (Cl-), nitrate (NO3-) and sulfate (SO4 2-)) and bacterial counts were studied for a period of ten days in November 2015. In addition, a health-based survey of patients attending the institute's hospital during those days was conducted to evaluate the risk level due to fireworks burning. RESULTS: The mean PM10 concentration during Diwali, 311 µg/m3, was 81% higher than other days and 3.1-times higher the Indian National Ambient Air Quality Standards. While noise levels were increased by 65%, the concentration of bacteria in PM10 was reduced by 39% during Diwali compared to other days. The concentrations of metals, cations and anions were increased by 51%, 72% and 77%, respectively. A health study conducted during the analysis period revealed an increase in hospital admissions in the campus due to respiratory symptoms. The higher concentrations of metals during the Diwali period resulted in a 0.5% increase in the hazard index. CONCLUSIONS: The present study suggests that reducing fireworks during Diwali could reduce pollutant concentrations and result in potential health benefits. PARTICIPANT CONSENT: Obtained. ETHICS APPROVAL: The study and survey design were approved by the Institutional Bioethics Committee of the Indian Institute of Technology, Guwahati. COMPETING INTERESTS: The authors declare no competing financial interests.