Geographic information system-based determination of priority monitoring areas for hazardous air pollutants in an industrial city.

Industrial cities are hotspots for many hazardous air pollutants (HAPs), which are detrimental to human health. We devised an identification method to determine priority HAP monitoring areas using a comprehensive approach involving monitoring, modeling, and demographics. The methodology to identify the priority HAP monitoring area consists of two parts: (1) mapping the spatial distribution of selected categories relevant to the target pollutant and (2) integrating the distribution maps of various categories and subsequent scoring. The identification method was applied in Ulsan, the largest industrial city in South Korea, to identify priority HAP monitoring areas. Four categories related to HAPs were used in the method: (1) concentrations of HAPs, (2) amount of HAP emissions, (3) the contribution of industrial activities, and (4) population density in the city. This method can be used to select priority HAP monitoring areas for intensive monitoring campaigns, cohort studies, and epidemiological studies.

Passive Air Sampling of PCDD/Fs, PCBs, PAEs, DEHA, and PAHs from Informal Electronic Waste Recycling and Allied Sectors in Indian Megacities.

Xenobiotic chemical emissions from the informal electronic waste recycling (EW) sector are emerging problem for developing countries, with scale and impacts that are yet to be evaluated. We report an intensive polyurethane foam disk passive air sampling study in four megacities in India to investigate atmospheric organic pollutants along five transects viz., EW, information technology (IT), industrial, residential, and dumpsites. Intraurban emission sources were estimated and attributed by trajectory modeling and positive matrix factorization (PMF). ∑17PCDD/Fs, ∑25PCBs, ∑7plasticizers, and ∑15PAHs concentrations ranged from 3.1 to 26 pg/m3 (14 ± 7; Avg ± SD), 0.5-52 ng/m3 (9 ± 12); 7.5-520 ng/m3, (63 ± 107) and 6-33 ng/m3 (17 ± 6), respectively. EW contributed 45% of total PCB concentrations in this study and was evidenced as a major factor by PMF. The dominance of dioxin-like PCBs (dl-PCBs), particularly PCB-126, reflects combustion as the possible primary emission source. PCDD/Fs, PCBs and plasticizers were consistently highest at EW transect, while PAHs were maximum in industrial transect followed by EW. Concentrations of marker plasticizers (DnBP and DEHP) released during EW activities were significantly higher (p < 0.05) in Bangalore than in other cities. Toxic equivalents (TEQs) due to dl-PCBs was maximum in the EW transect and PCB-126 was the major contributor. For both youth and adult, the highest estimated inhalation risks for dl-PCBs and plasticizers were seen at the EW transect in Bangalore, followed by Chennai and New Delhi.

Atmospheric polychlorinated biphenyls in a non-metropolitan city in northern India: Levels, seasonality and sources.

Recent studies from India reported polychlorinated biphenyls (PCBs) associated with incomplete combustion processes. In this study we have monitored atmospheric PCBs in Agra, a non-metropolitan city of northern India. During first month of summer and winter of 2017, polyurethane foam based passive air sampler (PUF-PAS) was deployed at each of 14 locations across urban, suburban and rural transects and one background site. Range of Σ25PCBs varied between 25 and 1433 pg/m3 (Avg ± Stdev: 460 ± 461) in summer and 26-205 pg/m3 (Avg ± Stdev: 106 ± 59) in winter. Mean Σ25PCBs concentration, showed an urban > suburban > rural trend in summer while, in winter a rural > urban > suburban trend was observed. PCB-52 was the dominant congener and after excluding this congener no significant difference was observed between summer and winter PCB concentrations. Using a combination of K-means cluster and principal component analysis (PCA) four major source types were identified. Open burning source accorded 80% of atmospheric PCBs, majorly indicator PCBs while the remaining 20% was contributed by atmospheric transport, petrogenic combustion and biomass burning. From the ten days back trajectory of the air mass it can be suggested that atmospheric transport from the hotspots resulted in a minor percentage of dioxin like PCBs in Agra. Maximum TEQs was accorded by PCB-77 (30%) and it is consistent with previous observations from Agra. Levels observed in the current study are well within the public health guideline based on inhalation unit risk (10 ng/m3) and United States Environmental Protection Agency's regional screening level high risk tier (4.9 ng/m3) for ambient air.

Atmospheric polychlorinated biphenyls from an urban site near informal electronic waste recycling area and a suburban site of Chennai city, India.

Recent studies evidenced informal electronic waste (e-waste) recycling as a potential source of polychlorinated biphenyls (PCBs) in the metropolitan environment of India. Given the recent evidences on the release of hazardous organic compounds from the informal e-waste recycling workshops in the Chennai city, we have conducted high volume air sampling in an urban site close to the informal e-waste recycling corridor and in a suburban site located about 35 km away from the urban center. Weekly diurnal gaseous and particulate phase samples were collected from both urban and suburban sites during summer and winter samples were collected only from suburban site. Mean atmospheric PCB levels in the urban site (Avg ± Stdev, 46 ± 16 ng/m3) is several orders of magnitude higher than suburban summer (10 ± 12 ng/m3) and winter (4 ± 3 ng/m3). Back trajectories originating from the land seems to have impacted the samples recorded with maximum PCB concentration. No significant difference was seen between summer and winter atmospheric PCBs in the suburban site. In urban site, PCB-52 and dioxin like PCBs (dl-PCBs) have increased from the past observations with maximum PCB-52 concentration in night time samples. Positive matrix factorization source-receptor model outputs suggest that in the urban centers, open burning in municipal dumpsites is a major source for PCB-52, while dl-PCBs were related to e-waste recycling by the informal sector. Exponential increment in most toxic non-ortho dl-PCBs proclaims the severity of on-going sources which contributed to the high toxic equivalency (TEQs) upto 105 pg TEQ/m3.

PCBs and PCDD/Fs in soil from informal e-waste recycling sites and open dumpsites in India: Levels, congener profiles and health risk assessment.

Growth of informal electronic waste (e-waste) recycling sector is an emerging problem for India. The presence of halogenated compounds in e-wastes may result in the formation of persistent organic pollutants like polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) during recycling processes. We therefore investigated PCBs and PCDD/Fs in surface soils explicitly from the informal e-waste recycling sites and nearby open dumpsites of major metropolitan cities from four corners of India, viz., New Delhi (North), Kolkata (East), Mumbai (West) and Chennai (South). In the informal e-waste recycling sites, the range of Σ26PCBs (0.4-488ng/g) and Æ©PCDD/Fs (1.0-10.6ng/g) were higher than Æ©26PCBs (0.3-21ng/g) and Æ©PCDD/Fs (0.15-7.3ng/g) from open dumpsites. In the e-waste sites, Æ©PCDDs were found with increasing trend from Æ©TetraCDD to OctaCDD, whereas Æ©PCDFs showed a reverse trend. The dominance of PCDF congeners and maximum toxicity equivalents (TEQ) for both PCDDs (17pg TEQ/g) and PCDFs (82pg TEQ/g) at Mandoli in New Delhi has been related to intensive precious metal recovery process using acid bath. Among dumpsites, highest TEQ for PCDD/Fs was observed at Kodangaiyur dumpsite of Chennai (CNDS-02, 45pg TEQ/g). Positive Matrix Factorization (PMF) model identified distinct congener pattern based on the functional activities, such as e-waste dismantling, shredding, precious metal recovery and open burning in dumpsites. E-waste metal recovery factor was loaded with 86-91% of PCB-77, -105, -114, -118 and 30% of PCB-126, possibly associated with the burning of wires during the copper extraction process. Almost 70% of the Æ©26PCB concentrations was comprised of the dioxin-like PCB congeners with a maximum concentration of 437ng/g at New Moore market in Chennai, followed by Wire Lane (102ng/g), in Mumbai. We speculate that PCB-126 might have resulted from combustion of plastic materials in e-waste stream and dumped waste.

Polychlorinated biphenyls in settled dust from informal electronic waste recycling workshops and nearby highways in urban centers and suburban industrial roadsides of Chennai city, India: Levels, congener profiles and exposure assessment.

Polychlorinated biphenyls (PCBs) were quantified in settled dust collected from informal electronic waste (e-waste) recycling workshops and nearby highways in the urban centers and roadside dust from the suburban industrial belt of Chennai city in India. Further dust samples were subjected to a high resolution field emission scanning electron microscope equipped with an energy dispersive X-ray spectrometer (FESEM/EDX) to characterize the shape, size and elemental composition of the dust particles. Geomean of total PCB concentration followed the following order: informal e-waste metal recovery workshops (53ngg-1)>e-waste dismantling sites (3.6ngg-1)>nearby highways (1.7ngg-1)>suburban industrial roadsides (1.6ngg-1). In e-waste workshops, tetra, penta and hexa-PCB homologs contributed two third of Σ26PCB concentration. Informal e-waste recycling workshops contributed more than 80% concentration of all the PCB congeners loaded in the first principal component. Predominance of dioxin like PCBs, PCB-l14, -118 and -126 in the e-waste metal recovery sites were presumably due to combustion and pyrolytic processes performed during recycling of electrical components. According to the morphology and elemental composition, settled dust from e-waste workshops were irregular particles heavily embedded with toxic metals and industrial roadside dust were distinct angular particles. FESEM revealed that average particle size (in Ferret diameter) increased in the following order: e-waste recycling workshops (0.5µm)