| 1. |
- Alamdar, Ambreen, et al.
(författare)
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Human Arsenic exposure via dust across the different ecological zones of Pakistan
- 2016
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier. - 0147-6513 .- 1090-2414. ; 126, s. 219-227
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Tidskriftsartikel (refereegranskat)abstract
- The present study aims to assess the arsenic (As) levels into dust samples and its implications for human health, of four ecological zones of Pakistan, which included northern frozen mountains (FMZ), lower Himalyian wet mountains (WMZ), alluvial riverine plains (ARZ), and low lying agricultural areas (LIZ). Human nail samples (N=180) of general population were also collected from the similar areas and all the samples were analysed by using ICP-MS. In general the higher levels (p < 0.05) in paired dust and human nail samples were observed from ARZ and LIZ than those of other mountainous areas (i.e., WMZ and FMZ), respectively. Current results suggested that elevated As concentrations were associated to both natural, (e.g. geogenic influences) and anthropogenic sources. Linear regression model values indicated that As levels into dust samples were associated with altitude (r(2)=0.23), soil carbonate carbon density (SCC; r(2)=033), and population density (PD; r(2)=0.25). The relationship of paired dust and nail samples was also investigated and associations were found for As-nail and soil organic carbon density (SOC; r(2)=0.49) and SCC (r(2)=0.19) in each studied zone, evidencing the dust exposure as an important source of arsenic contamination in Pakistan. Risk estimation reflected higher hazard index (HI) values of non carcinogenic risk (HI > 1) for children populations in all areas (except FMZ), and for adults in LIZ (0.74) and ARZ (0.55), suggesting that caution should be paid about the dust exposure. Similarly, carcinogenic risk assessment also highlighted potential threats to the residents of LLZ and ARZ, as in few cases (5-10%) the values exceeded the range of US -EPA threshold limits (10'6-10-4).
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| 2. |
- Eqani, Syed Ali Musstjab Akber Shah, et al.
(författare)
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Mercury contamination in deposited dust and its bioaccumulation patterns throughout Pakistan
- 2016
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 569, s. 585-593
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Tidskriftsartikel (refereegranskat)abstract
- Mercury (Hg) contamination of environment is a major threat to human health in developing countries like Pakistan. Human populations, particularly children, are continuously exposed to Hg contamination via dust particles due to the arid and semi-arid climate. However, a country wide Hg contamination data for dust particles is lacking for Pakistan and hence, human populations potentially at risk is largely unknown. We provide the first baseline data for total mercury (THg) contamination into dust particles and its bioaccumulation trends, using scalp human hair samples as biomarker, at 22 sites across five altitudinal zones of Pakistan. The human health risk of THg exposure via dust particles as well as the proportion of human population that are potentially at risk from Hg contamination were calculated. Our results indicated higher concentration of THg in dust particles and its bioaccumulation in the lower Indus-plain agricultural and industrial areas than the other areas of Pakistan. The highest THg contamination of dust particles (3000 ppb) and its bioaccumulation (2480 ppb) were observed for the Lahore district, while the highest proportion (>40%) of human population was identified to be potentially at risk from Hg contamination from these areas. In general, children were at higher risk of Hg exposure via dust particles than adults. Regression analysis identified the anthropogenic activities, such as industrial and hospital discharges, as the major source of Hg contamination of dust particles. Our results inform environmental management for Hg control and remediation as well as the disease mitigation on potential hotspots.
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| 3. |
- Shen, Xiantao, et al.
(författare)
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Molecular imprinting for removing highly toxic organic pollutants
- 2012
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Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1364-548X. ; 48:6, s. 788-798
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Tidskriftsartikel (refereegranskat)abstract
- Molecular imprinting technology allows synthesis of polymers with specific recognition ability towards target pollutants, which show potential to selectively remove Highly Toxic Organic Pollutants (HTOPs) in the presence of common organic matrices that are thousands of times more abundant than the targets. This feature article summarizes the current development of molecular imprinting for removing HTOPs from polluted water, with a special emphasis on the application of molecularly imprinted polymers to improve the efficiency of photocatalytic and biological degradation of HTOPs in wastewater.
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| 4. |
- Sohail, Muhammad, et al.
(författare)
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Persistent organic pollutant emission via dust deposition throughout Pakistan : Spatial patterns, regional cycling and their implication for human health risks
- 2018
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 618, s. 829-837
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Tidskriftsartikel (refereegranskat)abstract
- In the current study, Persistent Organic Pollutants (POPs) in outdoor dustfall was monitored for the first time along the Indus river system of Pakistan. Among the studied OCPs (ng/g, dry weight), DDTs (0.16-62) were the predominant contaminants identified in deposited dust followed by HCHs (0.1-10.2), HCB (0.09-7.4) and chlordanes (0.1-2.8). The indicative diagnostic ratio for DDTs and HCHs suggested recent emission of DDTs as well as historical emission of both chemicals in regions where they were used for crop protection and malarial control. The levels of Sigma(31)PCBs (ng/g, dry weight) in dust ranged from 0.95-125, and compositional profiles suggested arochlor-1248, -1254 commercial mixtures as source. A few exceptions were samples from urban areas that reflected the use of aroclor-1260, and-1262 and/or unintentional leakage from several industrial processes. The WHO05-TEQ values for dioxin-like PCBs (with major contributions of PCB-126) were found to be 0.07-34.5 (median; 1.87) pg TEQ g(-1) dw for all the studied samples. Correlation analysis identified that DDTs, HCHs, HCB and PCBs were significantly associated (r = 90; p < 0.01) with dusts collected in proximity to urban centers with widespread anthropogenic activities in these areas. A few cases where high levels of POPs from remote mountain highlands were detected, point to the potential for long range transport of these chemicals. Human risk assessment analysis of contaminated dust showed that DDTs and PCBs are major constituent chemicals of concern with regard to the development of cancer in children, with ingestion being the main route of exposure of dust-borne DDTs (0.12-1.03 x 10(-6)) and PCBs (0.86-12.43 x 10(-6)).
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