Publications (5)0.48 Total impact
- [Show abstract] [Hide abstract] ABSTRACT: Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo-p-furans (PCDFs) are unintentionally formed during inefficient combustions and as a by-product. Due to their resistance to degradation and their toxic effect on health, PCDD/Fs are listed by the Stockholm Convention as persistent organic pollutants (POPs). Once released into the atmosphere, most of them are adsorbed to air particles and transported away from sources in atmosphere. India signed the Stockholm Convention India agreeing thereby to reduce and eliminate the use of POPs. The German agency for Technical Cooperation helped develop facilities for mon-itoring POPs at a national level in Delhi. This paper presents the data generated during a training assignment for Central Pollution Control Board officials at the German laborato-ry. Air borne particulate matter (<PM 10) was collected from 6 different locations in Delhi, India and analyzed in a German laboratory for 17 congeners of PCDD/Fs. The concentrations of ∑PCDD/Fs ranged between 1720-9010 fg m -3 (mean 5559 fg m -3) and their toxic equivalency values ranged from 67 to 460 fg I-toxic equiva-lent quantities (TEQ) m -3 , with an average of 239 fg I-TEQ m -3 which was lower than the ambient air standards. The dominant con-geners were octachlorinated dibenzo-p-dioxin (OCDD), octachlorinated dibenzo-p-furans (OCDF), 1,2,3,4,6,7,8-heptachlorinated diben-zo-p-furans, and 1,2,3,4,6,7,8-heptachlorinated dibenzo-p-dioxin. The contributions of individ-ual homologs for ∑PCDDs/Fs I-TEQ was in the order of OCDD (31%)>HCDF (21%)>hexa-chlorodibenzofurans (13%)=OCDF (13%)> HCDF (12%) and other individual congeners contribute less than 5%. High chlorinated con-geners contributed with more than 80% for ∑PCDD/Fs I-TEQ. Rough estimates of tolerable daily intake (TDI) shows low health risk of exposure to ∑PCDD/Fs with inhalation of 0.098 pg I-TEQ kg -1 day -1 for adult and 0.152 pg TEQ kg -1 day -1 for children, which is much lower than World Health Organization recom-mended TDI for dioxins.
- [Show abstract] [Hide abstract] ABSTRACT: A study was conducted to assess the levels of organic pollutants i.e. organochlorine pesticides, (OGPs), organophosphate pesticides (OPPs) and herbicides, in sediments from nine major municipal drains in Delhi, India. Sediment samples from Delhi's municipal drains were extracted with acetone/dichloromethane (l:lv/v) and analyzed using GC and HPLC. The average concentration of ΣOCPs, ΣOPPs and Σherbicides was 27.26±9.7 ng g-1 (dry wt.), 80.89±22.4 ng g-1 (dry wt.) and 16.20±4.45 ng g-1(dry wt.), respectively. Among OCPs ΣHCH alone accounts 63% followed by ΣDDT (16%), Xendosulphan (13%) and drins 8%. The ratio of p,p'-DDT/ΣDDT (0.23), p,p'-DDT/p,p'-DDE (0.26) and o,p'-DDT/p,p'-DDT (<0.01) indicates the aged mixture or past usage of DDT and no dicofol type DDT. Among OPPs Chlorpyriphos was the dominant pollutant with 89% of total OPPs. Pendimethalin accounts 77% of total herbicides followed by Butachlor (14%) and Alachlor (9%). The level of herbicides, OCPs and OPPs in this study were compared with Canadian Sediment Quality Guidelines, Interim Sediment Quality Guidelines (ISQG) and Probable Effect Level (PEL) and found much lower than fresh water sediment guideline values. However, it is recommended that regular intensive assessment for persistent organic pollutants and heavy metals to be conducted, due to environmental concerns.
- [Show abstract] [Hide abstract] ABSTRACT: Residues of organochlorine pesticides (OCPs) were measured in cauliflower from West Bengal, India. The levels of OCPs were ranged between, 0.41 – 10.71 µg kg -1 (wet wt.), and the mean concentration of DDT, HCH and endosulphan was 3.31±0.52 µg kg -1 (wet wt), 2.63±0.61 µg kg -1 (wet wt), and 0.91±0.30 µg kg -1 (wet wt) respectively. The ratio of α-HCH to γ-HCH isomers (α/γ HCH ratio) ranged 0.09 to 3.37, which reflects the use of lindane as well as technical HCH. The ratio of p,p'-DDT/p,p'-DDE, p,p'-DDT/∑DDT and (DDE+DDD)/∑DDT, was 0.98, 0.27 and 0.66 respectively, indicates contamination with fresh input of aged mixture of DDTs. The cauliflowers from West Bengal had levels of OCPs much below than the MRLs, indicating minimal health risk to the consumers. However, it is recommended that regular intensive assessment for persistent organic pollutants to be conducted, due to human health concerns.