The state of scientific evidence on air pollution and human health in Nepal

Gurung, Anobha; Bell, Michelle L.

doi:10.1016/j.envres.2013.03.007

Cited by 47 publications

(35 citation statements)

References 66 publications

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“…The Kathmandu Valley is shaped like a circular bowl with a 630 km 2 watershed and 340-km 2 flat floors at approximately 1300 m above mean sea level surrounded by a rim of hills 500-3000 m above the valley floor. The valley comprises nearly 3.5 million residents and has a severe air pollution problem (Aryal et al, 2008;Kando et al, 2005;Gurung and Bell, 2013). Only one study examined ambient PAHs in this region, and it reported extremely high total PAH concentrations (640 ng/m 3 ) in Kathmandu in winter (Kishida et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Characteristics and sources of polycyclic aromatic hydrocarbons in atmospheric aerosols in the Kathmandu Valley, Nepal

Chen

Kang

et al. 2015

Science of The Total Environment

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• High concentrations of 4-6 ring PAHs were reported in the atmosphere of Kathmandu.• PAH concentrations in non-monsoon season were higher than those in monsoon season.• PAH ratios indicated that diesel and biomass fuels were main emission sources.• Toxic equivalent concentration of PAHs was 26 times higher than the WHO guideline. The Kathmandu Valley in the foothills of the Himalayas, where the capital city of Nepal is located, has one of the most serious air pollution problems in the world. In this study, total suspended particle (TSP) samples collected over a year (April 2013-March 2014 in the Kathmandu Valley were analyzed for determining the concentrations of 15 priority particle-bound polycyclic aromatic hydrocarbons (PAHs). The TSP and PAH concentrations were extremely high, with annual average concentration being 199 ± 124 μg/m 3 and 155 ± 130 ng/m 3 , respectively, which are comparable to those observed in Asian cities such as Beijing and Delhi. The TSP and PAH concentrations varied considerably, with the seasonal average concentration being maximal during the post-monsoon season followed by, in descending order, the winter, pre-monsoon, and monsoon seasons. In the winter and premonsoon seasons, ambient TSP and PAH concentrations increased because of emissions from brick kilns and the use of numerous small generators. Moreover, in the pre-monsoon season, forest fires in the surrounding regions influenced the TSP and PAH concentrations in the valley. PAHs with 4 to 6 rings constituted a predominant proportion (92.3-93.3%) of the total PAHs throughout the year. Evaluation of diagnostic molecular ratios indicated that the atmospheric PAHs in the Kathmandu Valley originated mainly from diesel and biomass G R A P H I C A L A B S T R A C T a b s t r a c t a r t i c l e i n f o Contents lists available at ScienceDirectScience of the Total Environment j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / s c i t o t e n v combustion. The toxic equivalent quantity (TEQ) of particle phase PAHs ranged between 2.74 and 81.5 ng TEQ/ m 3 , which is considerably higher than those reported in other South Asian cities, and 2-80 times higher than the World Health Organization guideline (1 ng TEQ/m 3 ). This suggests that ambient PAH levels in the Kathmandu Valley pose a serious health risk to its approximately 3.5 million residents.

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Section: Introductionmentioning

confidence: 99%

Characteristics and sources of polycyclic aromatic hydrocarbons in atmospheric aerosols in the Kathmandu Valley, Nepal

Chen

Kang

et al. 2015

Science of The Total Environment

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“…The primary reasons for poor air quality in fast growing cities are emissions from rapidly increasing yet poorly maintained vehicles (Rakowska et al, 2014), and industries with no or limited pollution control (Lim et al, 2010) to meet the needs of growing population and demands, as well as open burning of municipal waste and agro-residues which are common in developing countries (Shakya et al, 2010). This poses a significant threat to human health (Gurung and Bell, 2013), environmental degradation (Zhang et al, 2012), and economic stability (Dhimal, 2009).…”

Section: Introductionmentioning

confidence: 99%

Variability of Anthropogenic Gases: Nitrogen Oxides, Sulfur Dioxide, Ozone and Ammonia in Kathmandu Valley, Nepal

Kiros

Shakya

Rupakheti

et al. 2016

Aerosol Air Qual. Res.

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Kathmandu Valley is one of the largest and most polluted metropolitan regions in the Himalayan foothills. Rapidly expanding urban sprawl and a growing fleet of vehicles, and industrial facilities such as brick factories across the valley have led to conditions where ambient concentrations of key gaseous air pollutants are expected to exceed Nepal's National Ambient Air Quality Standards (NAAQS) and World Health Organization (WHO) guidelines. In order to understand the spatial variation of the trace gases in the Kathmandu Valley, passive samples of SO 2 , NO x , NO 2 , NH 3, and O 3 were collected simultaneously from fifteen locations between March and May 2013. A follow-up study during two separate campaigns in 2014 sampled these gases, except ammonia, one site at a time from thirteen urban, suburban and rural stationary sites. In 2013, urban sites were observed to have higher weekly averaged NO 2 and SO 2 (22.4 ± 8.1 µg m -3 and 14.5 ± 11.1 µg m -3 , respectively) than sub-urban sites (9.2 ± 3.9 µg m -3 and 7.6 ± 2.8 µg m -3 , respectively). Regions located within 3 km of brick factories had higher SO 2 concentrations (22.3 ± 14.7 µg m -3 ) than distant sites (5.8 ± 1.1 µg m -3 ). Higher O 3 (108.5 ± 31.4 µg m -3 ) was observed in rural locations compared to urban sites (87.1 ± 9.2 µg m -3 ), emphasizing the importance of meteorological factors and precursor species for ozone production and titration. Parallel to previous studies, these results suggest that ground-level O 3 , as its levels frequently exceeded guidelines throughout the sampling periods, is an important concern throughout the valley. NH 3 near polluted rivers and SO 2 around brick factories are also important pollutants that need more intensive monitoring, primarily due to their importance in particulate matter formation chemistry.

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“…Insufficient knowledge of air pollution sources in South Asia hinders the development of pollution mitigation strategies to protect public health (Gurung and Bell, 2013) and model representation of air quality and climate on local to global scales (Adhikary et al, 2007;Bond et al, 2013). Prevalent, but under-characterized combustion emission sources in South Asia include traffic, brick kilns, garbage burning, cooking stoves, and the open burning 20 of biomass.…”

Section: Introductionmentioning

confidence: 99%

Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): Emissions of particulate matter from wood and dung cooking fires, garbage and crop residue burning, brick kilns, and other sources

Stockwell¹,

Bhave²,

Praveen³

et al. 2017

Preprint

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Abstract.The Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) characterized widespread and 20 under-sampled combustion sources common to South Asia, including brick kilns, garbage burning, diesel and gasoline generators, diesel groundwater pumps, idling motorcycles, traditional and modern cooking stoves and fires, crop residue burning, and a heating fire. Fuel-based emission factors (EF; with units of pollutant mass emitted per kg of fuel combusted) were determined for fine particulate matter (PM 2.5 ), organic carbon (OC), elemental carbon (EC), inorganic ions, trace metals, and organic species. For the forced draught zig-zag brick 25 kiln, EF PM2.5 ranged 12-19 g kg -1 with major contributions from OC (7%), sulfate expected to be in the form of sulfuric acid (31.9%), and other chemicals not measured (e.g., particle bound water). For the clamp kiln, EF PM2.5 ranged 8-13 g kg -1 , with major contributions from OC (63.2%), sulfate (20.8%), and ammonium (14.2%). Our brick kiln EF PM2.5 values may exceed those previously reported, partly because we sampled emissions at ambient temperature after emission from the stack or kiln allowing some particle-phase OC and sulfate to form from 30 gaseous precursors. The combustion of mixed household garbage under dry conditions had an EF PM2.5 of 7.4 ± 1.2 g kg -1 , whereas damp conditions generated the highest EF PM2.5 of all combustion sources in this study, reaching up to 125 ± 23 g kg -1 . Garbage burning emissions contained relatively high concentrations of polycyclic aromatic compounds (PAHs), triphenylbenzene, and heavy metals (Cu, Pb, Sb), making these useful markers of this source. A variety of cooking stoves and fires fueled with dung, hardwood, twigs, and/or other biofuels were ), while biogas had no detectable PM emissions. Idling motorcycle emissions were evaluated before and after routine servicing at a local shop, which decreased EF PM2.5 from 8.8 ± 1.3 g kg -1 to 0.71 ± 0.45 g kg -1 when averaged across five motorcycles. Organic species analysis indicated that this reduction in PM 2.5 was largely due to a decrease in emission of motor oil, probably from the crankcase. The EF and chemical emissions profiles developed in this 10 study may be used for source apportionment and to update regional emission inventories.

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The state of scientific evidence on air pollution and human health in Nepal

Cited by 47 publications

References 66 publications

Characteristics and sources of polycyclic aromatic hydrocarbons in atmospheric aerosols in the Kathmandu Valley, Nepal

Characteristics and sources of polycyclic aromatic hydrocarbons in atmospheric aerosols in the Kathmandu Valley, Nepal

Variability of Anthropogenic Gases: Nitrogen Oxides, Sulfur Dioxide, Ozone and Ammonia in Kathmandu Valley, Nepal

Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): Emissions of particulate matter from wood and dung cooking fires, garbage and crop residue burning, brick kilns, and other sources

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