Correlation Between Toxic Elements and Pesticide Residues in Medicinal Herbs Available in Pharmaceutical Market.

The use of medicinal plants for self-medication of minor health conditions has become a widespread practice in contemporary society. Few consumes, however, question the contamination of these products with toxic factors resulting from the planet's increasingly polluted environment. This paper presents the levels of five toxic elements (As, Cr, Pb, Cd, and Hg) and nine organochlorine pesticides (hexachlorobenzene (HCB), lindane, heptachor, aldrin, dieldrin, endrin, p,p'DDE, p,p'DDD, and p,p'DDT) in 14 brands of regularly consumed medicinal products in Romania. The toxic elements content was determined using energy-dispersive X-ray fluorescence (EDXRF) technique, and organochlorine pesticide residues (OPCs) were quantified using gas-chromatographic method, equipped with electron capture detector (GC-ECD). The results show that in the case of Cr, Cd, and Hg, the concentrations exceeded the limit values established by World Health Organisation (WHO) for raw herbal material. The higher level of OPCs (such as p,p'DDD, p,p'DDT, aldrin, and dieldrin) was found in the samples of Hypericum perforatum-St. John's wort, Crataegus monogyna-hawthorn, and Epilobium parviflorum-hoary willowherb. The correlations between the content of toxic elements and pesticides were determined by statistical analysis. Hierarchical clustering technique was used to detect natural grouping between the toxic elements and pesticides. For herb samples, four clusters were identified, the strongest correlated cluster consisting of Pb, HCB, Cr, and Hg. A further analysis within this cluster suggested that Cr levels are statistically different from the rest of the elements.

Coming ecological risks of organochlorine pesticides and novel brominated flame retardants in the Yellow River Basin.

To conduct ecological risk assessment, food, water and soil samples were collected from five densely populated irrigation areas in the Yellow River Basin (YRB), and analyzed for organochlorine pesticides (OCPs) and novel brominated flame retardants (NBFRs). The results showed that the OCP residues (∑14OCP were 0.748 ng L-1, 13.1 ng g-1 dw and 3.22 ng g-1 dw in water, soil and maize) were generally within moderate levels in the YRB. Dichlorodiphenyltrichloroethane (DDT) residues dominated the OCPs, and potential ecological risks to aquatic and terrestrial organisms likely stemmed from dichlorodiphenyldichloroethylene (DDE) pollution in the upper reaches of the YRB in the Ningxia and Hetao Plain. The NBFR concentrations in the YRB were 90.9 pg L-1 in water, 21.1 pg g-1 dw in soil and 3.81 pg g-1 dw in maize. Positive correlations were observed between soil and maize contamination in the five irrigated districts, indicating a potential threat to grain security and human health risks caused by OCPs and NBFRs. Pollutants detected in soil and maize primarily originated from historical use (36.3 %), while the sources in water were more complex (64.4 %) and new inputs could not be excluded. Integrated health risks of human exposure to agricultural products and water from the YRB were acceptable. However, the ecological risk of the Ningxia Plain would further deteriorate to the medium risk after 2032. The increasing ecological risk of DDT in water indicates that regular monitoring should strengthen to ensure grain and water safety in the YRB.

Organochlorine pesticides in therapeutic teas and human health risk assessment.

This study evaluated commercially available therapeutic teas for their organochlorine pesticides (OCPs) residue levels to estimate the potential health risks associated with their prolonged consumption. Tea samples that were produced for therapeutic uses were obtained commercially. Organochlorine pesticide residues were extracted from the samples using the modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method and analysed using Gas Chromatography with Electron Capture Detector (GC-ECD). Results showed that the tea samples contained a large number of OCPs residue at levels that were significantly higher than the maximum residue limits (MRLs) set by the European Union (p > 0.05). Aldrin was detected in all samples, methoxychlor, and p,p'-DDT were detected in ≥88% of the samples while γ-HCH, δ-HCH, endosulfan II, and endosulfan sulphate were detected in ≥69% of the samples. Health risk assessment indicated that the highest risk of cancer was associated with aldrin.

Spatial distribution and sources of pesticidal persistent organic pollutants in the Hooghly riverine sediment.

Given the extensive indiscriminate usage in the past and limited ongoing use, organochlorine pesticides (OCPs) have been widely reported in the Hooghly riverine environment. Hence, surface riverine sediment samples were collected along the urban and suburban transects of the Hooghly River and OCPs were quantified in gas chromatography mass spectrometry (GC-MS). Mean concentration of HCH, DDT, and endosulfan was 5 ng g-1, 10 ng g-1, and 4 ng g-1 respectively. DDT was dominant among all the OCPs and contributed nearly 40% to the total OCPs possibly due to the ongoing use of DDT for vector control programs. Diagnostic ratios suggest recent source of lindane, DDT, and endosulfan. Using OCP concentration from previously published data in surface water during the same time frame, sediment-water partitioning of OCPs was estimated. Excluding α-HCH and γ-HCH in few pockets, majority of the OCPs tend to partition more on to sediment. Comparing the sediment concentration with the sediment quality guideline values, risk on ecological integrities was indicated due to DDT and HCH contamination. Suburban sites indicated higher risk than urban sites according to the calculated sediment quality guideline quotient (SQGQ). A brief review on the approach to pesticidal POP pollution management in India revealed that older management approaches should be replaced with a unique, integrated, and holistic system.

Profiling of heavy metal and pesticide residues in medicinal plants.

Application of medicinal plant to cure ailments has been practiced by several civilizations. Nowadays, contamination of heavy metals and pesticide residues in medicinal plant is a serious concern, due to toxic effects on human health. The present study was designed with an aim to quantify the heavy metals and pesticide residues in the 20 medicinal herbs, frequently sold in the local market as raw material without any quality assurance. The concentrations of the elements are as follows: copper (2.42-19.14 µgg-1), cadmium (0.01-2.10 µgg-1), chromium (17.63-58.63 µgg-1), iron (7.61-322.6 µgg-1), and lead (13.00-54.47 µgg-1), whereas total metal concentration ranged between 44.73 and 385.15 µgg-1. Among the organic pesticides, HCH (1.63-6.44 µgg-1) and DDT (0.63-7.14 µgg-1) isomers were found to be present in medicinal plant material. Result showed that lead and chromium concentrations in the herbs were above the permissible limits set by WHO. These herbs should be regularly checked for quality assurance before using raw or as a herbal formulation to avoid chronic exposure of metal and pesticides to human being.

Spatial distributions, source apportionment and ecological risk of SVOCs in water and sediment from Xijiang River, Pearl River Delta.

Xijiang River is an important drinking water source in Guangxi Province, China. Along the Xijiang River and surrounding tributary, the pollution profile of three important groups of semi-volatile organic compounds, including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and phthalate esters (PAEs), was analyzed. Relatively low levels of PAHs (64-3.7 × 102 ng L-1) and OCPs (16-70 ng L-1), but high levels of PAEs (7.9 × 102-6.8 × 103 ng L-1) occurred in the water. Comparatively, low levels of OCPs (39-1.8 × 102 ng g-1) and PAEs (21-81 ng g-1), but high levels of PAHs (41-1.1 × 103 ng g-1) were found in sediment. Principal component analyses for source identification indicated petroleum-derived residues or coal and biomass combustion, and vehicular emission was the main sources for PAHs. The OCPs sources of each category were almost independent, whereas the new input of HCHs and p,p'-DDTs probably existed in some areas. PAEs were mainly originated from personal care products of urban sewage, plastic and other industrial sources. Ecological risk through the risk quotient analysis indicated a small or significant potential adverse effect on fish, daphnia and green algae. Nevertheless, the integrated risk of all pollutants should be taken into account in future study.

Significance of Cooking Oil to Bioaccessibility of Dichlorodiphenyltrichloroethanes (DDTs) and Polybrominated Diphenyl Ethers (PBDEs) in Raw and Cooked Fish: Implications for Human Health Risk.

The present study examined the bioacessibility of DDTs and PBDEs in cooked fish (yellow grouper; Epinephelus awoara) with and without heating using the colon extended physiologically based extraction test. The bioaccessibility of DDTs and PBDEs increased from 60 and 26% in raw fish to 83 and 63%, respectively, after the addition of oil to raw fish. However, they decreased from 83 to 66% and from 63 to 40%, respectively, when oil-added fish were cooked. Human health risk assessment based on bioaccessible concentrations of DDTs and PBDEs in fish showed that the maximum allowable daily fish consumption rates decreased from 25, 59, and 86 g day-1 to 22, 53, and 77 g day-1 for children, youths, and adults, respectively, after fish were cooked with oil. These findings indicated that the significance of cooking oil to the bioaccessibility of DDTs and PBDEs in food should be considered in assessments of human health risk.

Intake of farmed Atlantic salmon fed soybean oil increases insulin resistance and hepatic lipid accumulation in mice.

BACKGROUND: To ensure sustainable aquaculture, fish derived raw materials are replaced by vegetable ingredients. Fatty acid composition and contaminant status of farmed Atlantic salmon (Salmo salar L.) are affected by the use of plant ingredients and a spillover effect on consumers is thus expected. Here we aimed to compare the effects of intake of Atlantic salmon fed fish oil (FO) with intake of Atlantic salmon fed a high proportion of vegetable oils (VOs) on development of insulin resistance and obesity in mice. METHODOLOGY/PRINCIPAL FINDINGS: Atlantic salmon were fed diets where FO was partly (80%) replaced with three different VOs; rapeseed oil (RO), olive oil (OO) or soy bean oil (SO). Fillets from Atlantic salmon were subsequently used to prepare Western diets (WD) for a mouse feeding trial. Partial replacement of FO with VOs reduced the levels of polychlorinated biphenyls (PCB) and dichloro-diphenyl-tricloroethanes (DDT) with more than 50% in salmon fillets, in WDs containing the fillets, and in white adipose tissue from mice consuming the WDs. Replacement with VOs, SO in particular, lowered the n-3 polyunsaturated fatty acid (PUFA) content and increased n-6 PUFA levels in the salmon fillets, in the prepared WDs, and in red blood cells collected from mice consuming the WDs. Replacing FO with VO did not influence obesity development in the mice, but replacement of FO with RO improved glucose tolerance. Compared with WD-FO fed mice, feeding mice WD-SO containing lower PCB and DDT levels but high levels of linoleic acid (LA), exaggerated insulin resistance and increased accumulation of fat in the liver. CONCLUSION/SIGNIFICANCE: Replacement of FO with VOs in aqua feed for farmed salmon had markedly different spillover effects on metabolism in mice. Our results suggest that the content of LA in VOs may be a matter of concern that warrants further investigation.

Obsolete pesticides and application of colonizing plant species for remediation of contaminated soil in Kazakhstan.

In Kazakhstan, there is a problem of finding ways to clean local sites contaminated with pesticides. In particular, such sites are the deserted and destroyed storehouses where these pesticides were stored; existing storehouses do not fulfill sanitary standards. Phytoremediation is one potential method for reducing risk from these pesticides. Genetic heterogeneity of populations of wild and weedy species growing on pesticide-contaminated soil provides a source of plant species tolerant to these conditions. These plant species may be useful for phytoremediation applications. In 2008-2009 and 2011, we surveyed substances stored in 80 former pesticide storehouses in Kazakhstan (Almaty oblast) to demonstrate an inventory process needed to understand the obsolete pesticide problem throughout the country, and observed a total of 354.7 t of obsolete pesticides. At the sites, we have found organochlorine pesticides residues in soil including metabolites of dichlorodiphenyltrichloroethane and isomers of hexachlorocyclohexane. Twenty-four of the storehouse sites showed pesticides concentrations in soil higher than maximum allowable concentration which is equal to 100 µg kg(-1) in Kazakhstan. Seventeen pesticide-tolerant wild plant species were selected from colonizing plants that grew into/near the former storehouse's pesticides. The results have shown that colonizing plant annual and biannual species growing on soils polluted by pesticides possess ability to accumulate organochlorine pesticide residues and reduce pesticide concentrations in soil. Organochlorine pesticides taken up by the plants are distributed unevenly in different plant tissues. The main organ of organochlorine pesticide accumulation is the root system. The accumulation rate of organochlorine pesticides was found to be a specific characteristic of plant species and dependent on the degree of soil contamination. This information can be used for technology development of phytoremediation of pesticide-contaminated soils.

A high-resolution historical sediment record of nutrients, trace elements and organochlorines (DDT and PCB) deposition in a drinking water reservoir (Lake Brêt, Switzerland) points at local and regional pollutant sources.

The (137)Cs and (210)Pb dating of a 61-cm long sediment core retrieved from a drinking water reservoir (Lake Brêt) located in Switzerland revealed a linear and relatively high sedimentation rate (~1 cm year(-1)) over the last decades. The continuous centimeter scale measurement of physical (porewater and granulometry), organic (C(org), P, N, HI and OI indexes) and mineral (C(min) and lithogenic trace elements) parameters therefore enables reconstructing the environmental history of the lake and anthropogenic pollutant input (trace metals, DDT and PCBs) at high resolution. A major change in the physical properties of the lowermost sediments occurred following the artificial rise of the dam in 1922. After ca. 1940, there was a long-term up-core increase in organic matter deposition attributed to enhance primary production and anoxic bottom water conditions due to excessive nutrient input from a watershed predominantly used for agriculture that also received domestic effluents of two wastewater-treatment plants. This pattern contrasts with the terrigenous element input (Eu, Sc, Mg, Ti, Al, and Fe) which doubled after the rising of the dam but continuously decreased during the last 60 years. By comparison, the trace metals (Cu, Pb and Hg) presented a slight enrichment factor (EF) only during the second part of the 20th century. Although maximum EF Pb (>2) occurred synchronously with the use of leaded gasoline in Switzerland (between ca. 1947 and 1985) the Hg and Cu profiles exhibited a relatively similar trend than Pb during the 20th century, therefore excluding the alkyl-lead added to petrol as the dominant (atmospheric) source of lead input to Lake Brêt. Conversely, the Cu profile that did not follow the decrease registered in Pb and Hg during the last 10 years, suggests an additional source of Cu probably linked to the impact of agricultural activities in the area. In absence of heavy industries in the catchment, the atmospheric deposition of DDT and PCBs via surface runoff followed the historical emissions of POPs in Switzerland. Such result highlights the regional contamination of freshwater resources by the large-scale emission of toxic industrial chemicals in the 1960s and 1970s as well as the efficiency of the regulatory measures subsequently taken.

Two multidimensional chromatographic methods for enantiomeric analysis of o,p'-DDT and o,p'-DDD in contaminated soil and air in a malaria area of South Africa.

In rural parts of South Africa the organochlorine insecticide DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) is still used for malaria vector control where traditional dwellings are sprayed on the inside with small quantities of technical DDT. Since o,p'-DDT may show enantioselective oestrogenicity and biodegradability, it is important to analyse enantiomers of o,p'-DDT and its chiral degradation product, o,p'-DDD, for both health and environmental-forensic considerations. Generally, chiral analysis is performed using heart-cut multidimensional gas chromatography (MDGC) and, more recently, comprehensive two-dimensional gas chromatography (GC×GC). We developed an off-line gas chromatographic fraction collection (heart-cut) procedure for the selective capturing of the appropriate isomers from a first apolar column, followed by reinjection and separation on a second chiral column. Only the o,p'-isomers of DDT and DDD fractions from the first dimension complex chromatogram (achiral apolar GC column separation) were selectively collected onto a polydimethylsiloxane (PDMS) multichannel open tubular silicone rubber trap by simply placing the latter device on the flame tip of an inactivated flame ionisation detector (FID). The multichannel trap containing the o,p'-heart-cuts was then thermally desorbed into a GC with time-of-flight mass spectrometry detection (GC-TOFMS) for second dimension enantioselective separation on a chiral column (ß-cyclodextrin-based). By selectively capturing only the o,p'-isomers from the complex sample chromatogram, (1)D separation of ultra-trace level enantiomers could be achieved on the second chiral column without matrix interference. Here, we present solventless concentration techniques for extraction of DDT from contaminated soil and air, and report enantiomeric fraction (EF) values of o,p'-DDT and o,p'-DDD obtained by a new multidimensional approach for heart-cut gas chromatographic fraction collection for off-line second dimension enantiomeric separation by (1)D GC-TOFMS of selected isomers. This multidimensional method is compared to the complementary technique of comprehensive GC×GC-TOFMS using the same enantioselective column, this time as the first dimension of separation.

Lipofuscin-like pigment in gonads of Sea Urchin Strongylocentrotus intermedius as a potential biomarker of marine pollution: a field study.

Accumulation of lipofuscin-like pigments (LLPs) has been shown to be an appropriate index of both age and stress in some aquatic invertebrates. In the present study, LLP was quantified by measuring its autofluorescence intensity (ex 450 nm/em 512 nm) in nutritive phagocytes (NPs) of sea urchins Strongylocentrotus intermedius inhabiting polluted and relatively clean areas of Japan Sea. To avoid variations in LLP content related to sea urchin reproductive condition, only developing gonads with acini occupied mostly by NPs were used for LLP quantification as well as semiquantitative histopathological analysis. LLP concentrations ranged from 0.0 to 4.57 ± 0.53% area fraction in female gonads and from 0.0 to 4.61 ± 0.35% in male gonads. The presence of specimens with extremely high LLP concentrations (>1.5%) in all examined samples, including specimens from the reference station, as well as the absence of strong correlations between LLP concentrations and several parameters related to pollution (heavy-metal concentrations in sea urchin gonads and concentrations of heavy metals, DDT, hexachlorocyclohexane, and total petroleum hydrocarbons in sediments), allow us to conclude that LLP content in sea urchin NPs can not be used as a biomarker in marine pollution monitoring.

Chlorinated pesticides: threats to health and importance of detection.

Although chlorinated pesticides have been mostly banned from use in the United States, their persistent presence in the environment poses an ongoing threat to health. Because of the lipophilic nature of chlorinated pesticides, they are bioaccumulative and difficult to excrete from the body. A select group of these xenobiotics is also associated with a wide range of health problems, identification of which would aid in disease prevention and reversal. Ongoing research by the Centers for Disease Control and Prevention now provides national standards for some of these compounds, allowing the clinician to evaluate levels in a patient. Serum samples are easily obtained and can reveal the presence of these xenobiotics. Eight of the most commonly found and harmful chlorinated pesticides are reviewed in this article, along with the most common sources of exposure and possible action steps.

Levels of organochlorine pesticides in crops and related products from Vojvodina, Serbia: estimated dietary intake.

Levels of 16 organochlorine pesticides (OCPs) were investigated in 39 composite samples of agricultural crops, related by-products, and foodstuffs collected in Vojvodina, Serbia, in 2002 through 2004. After extraction and cleanup, OCPs were determined by capillary gas chromatography using electron-capture detection. The highest mean level of 0.971 ng/g whole weight (ww) was found for alpha-HCH in wheat flour samples. OCPs levels were well lower than the respective maximum residue limits set by current European and Serbian regulations. Mean OCP levels were low (<1 ng/g ww) for all sample types. The most frequently determined residue was 4,4'-DDT (identified in 76.9% of all samples analyzed), followed by gamma-HCH (66.7%), beta-HCH (48.7%), and endosulfan II (41.0%). OCP levels were compared with data from other international surveys. Calculated daily intakes of OCPs by way of consumption of the crop products included in this study according to data of the Serbian National Institute for Statistics were compared with the acceptable daily intakes established by the Food and Agriculture Organization/World Health Organization. The average level of contamination of the Vojvodina diet was believed to be harmless regarding the studied food commodities.

Residues of 18 organochlorine pesticides in 30 traditional Chinese medicines.

We analyzed 30 different traditional Chinese medicines (TCMs) to determine levels of contamination with organochlorine pesticides (OCPs). We tested for 18 pesticides: benzene hexachloride (BHC, including alpha-BHC, beta-BHC, gamma-BHC, delta-BHC), heptachlor, heptachlor epoxide, tecnazene, pentachloronitrobenzene (PCNB), hexachlorobenzene, aldrin, methyl pentachlorophenyl sulphide (MPCPS), alpha-endosulfan, trans-chlorodane, cis-chlorodane, p,p'-DDE, o,p'-DDT, p,p'-DDD, and p,p'-DDT. The sample extracts were analyzed by GC-ECD. A total of 280 samples of 30 different TCMs were analyzed. Our results showed that 75.8% of samples contained at least one of the above pesticides. The pesticides detected were tecnazene, hexachlorobenzene, PCNB, heptachlor, aldrin, alpha-BHC, beta-BHC, gamma-BHC, delta-BHC, p,p'-DDE, o,p'-DDT, p,p'-DDD p,p'-DDT. More than 50% of samples contained alpha-BHC (55.8%) and PCNB (55.8%); hexachlorobenzene was detected in 40.9% of samples, tecnazene in 19.5%, gamma-BHC in 16.7% and p,p'-DDE in 16.0%. Less than 10% of samples contained beta-BHC, delta-BHC, heptachlor, aldrin, o,p'-DDT, p,p'-DDT and p,p'-DDD. None of the 280 samples contained heptachlor epoxide, MPCPS, alpha-endosulfan, trans-chlorodane, or cis-chlorodane. Concentrations of OCPs in four samples exceeded the maximum allowable residue limits (MRLs) specified in the PRC Pharmacopoeia 2005. The results indicate that the most common contaminants among the 280 samples were alpha-BHC, PCNB, hexachlorobenzene, and tecnazene. Our results suggest that contamination of TCMs with OCPs is widespread. The MRLs for other OCPs commonly found in TCMs (e.g. hexachlorobenzene and tecnazene) should be set as quickly as possible, and the MRLs of OCPs in other TCMs should be established.

Leaf-air transfer of organochlorine pesticides from three selected vegetables.

The leaf-air transfer of organochlorine pesticides (OCPs) in three kinds of vegetables, namely lettuce, romaine and garlic leaves was investigated. It was found that although the uptake of OCPs by the three selected vegetables was similar under controlled conditions, the depuration varied significantly among chemicals and plant species in terms of elimination rate, final residue of each OCPs, as well as the effect of temperature on the residue of OCPs in the vegetables. The results indicated that neither QCB nor HCB could be trapped tightly by any of the three selected vegetables, in contrast, p,p'-DDT could be retained effectively by all of them; the retainment of alpha-HCH, gamma-HCH, p,p'-DDE, was dependent on the vegetable species, of which the garlic leaf had the biggest ability to trap them. Our work provided insight into the behavior of OCPs in the agroecosystem.

Residual concentrations of micropollutants in benthic mussels in the coastal areas of Bohai Sea, North China.

Studies of heavy metals and organic pollutants in different benthic mussel species from Bohai Sea show that concentrations of Cd in mussels commonly exceed national biological quality standards. In addition, a site located in Laizhou Bay exhibits higher average concentrations of As, Hg and Pb with respect to the other sites. Residual levels of petroleum hydrocarbons at several sites in Liaodong Bay also exceed quality guidelines. Contents and compositional characteristics of DDT and its metabolites in mussels suggest the probability of recent inputs and potential ecological risks to the local benthic environment.

Studies on dechlorination of DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) using magnesium/palladium bimetallic system.

The aim of our investigation was to compare the rates of dechlorination of DDT using Mg0/Pd4+ system in two different reaction phases, namely, water-acetone and 0.05% biosurfactant in water. Since palladium is expensive and its toxicity effects are not well known we also examined the reuse efficiency of Pd0 immobilized on alumina for dechlorinating DDT. Studies on the dechlorination of DDT in water-acetone (1:1, v/v) and 0.05% biosurfactant phases revealed that the reaction followed second order kinetics and rate of reaction is dependent upon both initial concentrations of the target compound and Mg0/Pd4+. The presence of acid enhanced the rate of reaction by providing protons and preventing passivation of metal that occurs due to deposition of magnesium hydroxide. GC-MS analyses revealed the formation of completely dechlorinated hydrocarbon skeleton of DDT namely, diphenylethane (DPE), as the end product in both reaction phases (water-acetone and 0.05% biosurfactant in water) thereby implying the removal of all five chlorine atoms (three alkyl and two aryl) of DDT. The optimum ratio of water and acetone to facilitate successful dechlorination reaction was found to be 9:1. Results suggested that salt form (K2PdCl6) of palladium had higher potential to dechlorinate DDT as compared to pellet (Pd0-alumina) form (efficiencies of 95 and 36%, respectively, for 100 ppm initial concentration of DDT). We noted that Pd0-alumina pellets could be reused at least four times for successful dechlorination of DDT provided Mg0 granules are present in sufficient quantity. Technical grade DDT (50 ppm) containing significant amounts of DDD was dechlorinated almost completely by the Mg0/Pd4+ (10mg/0.2mg/ml) within 1h in water-biosurfactant phase. Our studies reveal that Mg/Pd system is a promising option due to its high reactivity and its ability to achieve complete dechlorination of DDT. This bimetallic system may be useful for designing indigenous permeable barriers or reactors for the treatment of DDT contaminated water.

Concentrations of organochlorine insecticides in edible oils from different regions of India.

In this study, organochlorine insecticides (OCPs), DDT metabolites and HCH isomers were quantified in mustard, groundnut and sunflower oils collected from different regions of India. The maximum level of 222.0 ng g(-1) and minimum level of 0.2 ng g(-1) of SigmaDDT were detected in mustard oil from Deoria and Varanasi while those of SigmaHCH i.e., 1500 ng g(-1) and 8.0 ng g(-1) in mustard oil from Deoria and Kanpur, respectively. However, the maximum total concentration of alpha-, beta- and gamma-HCH was in mustard oil, whereas maximum delta-HCH was in groundnut oil. However, the maximum percentage of p,p'-DDT was in mustard oil while maximum p,p'-DDE was in groundnut oil. The study calls for periodical monitoring to ensure safe supply of edible oils to consumers.

Environmental contaminants in fish and their associated risk to piscivorous wildlife in the Yukon River Basin, Alaska.

Organochlorine chemical residues and elemental contaminants were measured in northern pike (Esox lucius), longnose sucker (Catostomus catostomus), and burbot (Lota lota) from 10 sites in the Yukon River Basin (YRB) during 2002. Contaminant concentrations were compared to historical YRB data and to toxicity thresholds for fish and piscivorous wildlife from the scientific literature. A risk analysis was conducted to screen for potential hazards to piscivorous wildlife for contaminants that exceeded literature-based toxicity thresholds. Concentrations of total DDT (sum of p,p'-homologs; 1.09-13.6 ng/g), total chlordane (0.67-7.5 ng/g), dieldrin (<0.16-0.6 ng/g), toxaphene (<11-34 ng/g), total PCBs (<20-87 ng/g), TCDD-EQ (