Abilities of Co-cultures of Brown-Rot Fungus Fomitopsis pinicola and Bacillus subtilis on Biodegradation of DDT.

DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) is one of the pesticides that are hazardous for the environment and human health. Effective environmental-friendly treatment using co-cultures of fungi and bacteria is needed. In this study, the bacteria Bacillus subtilis at various volumes of 1, 3, 5, 7, and 10 mL (1 mL ≈ 6.7 × 108 CFU) were mixed into 10 mL of the brown-rot fungus Fomitopsis pinicola culture for degrading DDT during a 7-days incubation period. DDT was degraded by approximately 42% by F. pinicola during the 7-days incubation period. The addition of 10 mL of B. subtilis into F. pinicola culture showed the highest DDT degradation of approximately 86% during the 7-days incubation period. DDD (1,1-dichloro-2,2-bis(4-chlorophenyl)ethane), DDE (1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene), and DDMU (1-chloro-2,2-bis(4-chlorophenyl)ethylene) were detected as metabolic products from DDT degradation by co-cultures of F. pinicola and B. subtilis. Transformation pathway was proposed in which DDT was transformed into three pathways as follows: (1) dechlorination to DDD, (2) dehydrochlorination to DDE, and (3) formation of DDMU.

DDT, DDD, and DDE in soil of Xiangfen County, China: Residues, sources, spatial distribution, and health risks.

We collected and analyzed 128 surface soil samples from Xiangfen County for dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyldichloroethylene (DDE). Total DDT concentrations (DDTs; sum of p,p'-DDD, p,p'-DDE, and p,p'-DDT) ranged from ND to 427.81 ng g(-1) (dry weight, dw), with a mean of 40.26 ng g(-1) (dw). Among the three compounds, p,p'-DDD was the most dominant. The DDTs in Xiangfen County soils mainly originated from historical DDT use, but there were also new inputs likely related to dicofol use. The DDTs in Xiangfen County soils were mainly degraded under anaerobic conditions, and direct degradation to DDD was the main degradation route. Regions with relatively high concentrations of DDTs were mainly located in North and South Xiangfen County. In these regions, many soil samples contained p,p'-DDT as the predominant pollutant, suggestive of extensive new inputs of DDT. A health risk assessment revealed that there are no serious long-term health impacts of exposure to DDTs in soil, for adults or children.

Organochlorine pesticides, lead, and mercury in northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) from the Rolling Plains ecoregion of Texas and Oklahoma.

Northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) from the Rolling Plains ecoregion in Texas and Oklahoma were evaluated for organochlorine pesticides, Pb, and Hg. Of all organochlorine pesticides analyzed, only p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and p,p'-dichlorodiphenyldichloroethane (p,p'-DDD) were found in a few composite liver samples. Similarly, a small fraction of tissue samples had detectable levels of Hg (liver and breast) or Pb exceeding background concentrations (femur). Lead concentrations in a few individuals fell within the range associated with moderate toxicity.

Composition, distribution and risk assessment of organochlorine pesticides in soils from the Midway Atoll, North Pacific Ocean.

Concentrations of legacy organochlorine pesticides (OCPs), including dichlorodiphenyltrichloroethane (DDT) and its metabolites (e.g., DDE and DDD), and hexachlorocyclohexanes (HCHs) were determined in 111 soil samples from the Midway Atoll. OCPs were found in all samples analyzed, with predominance of α-HCH, p,p'-DDD and p,p'-DDT. The total concentrations ranged from 0 to 127 ng g(-1) with a median concentration of 17 ng g(-1) for HCHs and 1.4 to 643 ng g(-1) with a median concentration of 168 ng g(-1) for DDTs. The possible degradation pathways and potential sources of DDTs and HCHs were investigated. The total concentrations of DDTs and HCHs were used to evaluate the cancer risk probabilities in humans via ingestion, dermal contact and inhalation of soil particles. Very low cancer risk was found in all soil samples caused by ΣDDTs and ΣHCHs.

Health risk assessment of pesticides residue in maize and cowpea from Ejura, Ghana.

Low productivity in agriculture due to damage cause by pests has led to the application of pesticides to control pest infestation. Residues of pesticides applied on crops are often found in the food which can cause chronic effect on the health of humans who consume such products. The aim of this study is to measure pesticides residues in maize and cowpea and compare the values with stablished safety limits. A total of 37 pesticides comprising 15 organochlorines, 13 organophosphorus and 9 pyrethroids pesticides were identified in maize and cowpea samples obtained from farms in Ejura. Analytical methods included solvent extraction of the pesticide residues and their subsequent quantification using gas chromatograph equipped with Electron Capture Detector and Pulse Flame Photometric Detector after clean-up on alumina/activated charcoal column. The results showed that the mean concentration of pesticides in maize ranged from 0.001 to 0.103 mg kg(-1) for organochlorine pesticides, 0.002-0.019 mg kg(-1) for organophosphorus pesticides and 0.002-0.028 mg kg(-1) for pyrethroids pesticides. In cowpea the mean concentration ranged from 0.001 to 0.108 mg kg(-1) for organochlorine pesticides, 0.002-0.015 mg kg(-1) for organophosphorus pesticides and 0.001-0.039 mg kg(-1) for pyrethroids pesticides. Maximum Residue Limits for ß-HCH, ß-endosulfan, p,p'-DDE and p,p'-DDD were exceeded in both maize and cowpea samples. Health risk estimation revealed that residues of heptachlor, dieldrin, endrin, ß-endosulfna, γ-chlordane and chlorfenvinphos found in maize exceeded the Acceptable Daily Intake. Similarly the levels of heptachlor and p,p'-DDD found in cowpea also exceeded the Acceptable Daily Intake. This suggests a great potential for chronic toxicity to consumers of these food items.

Levels and seasonal variations of organochlorine pesticides in urban and rural background air of southern Ghana.

Urban, suburban and rural background air samples were collected in southern Ghana in 2008 employing polyurethane foam disc passive air samplers (PAS). PAS were analysed for organochlorine pesticides (OCPs), namely hexachlorocyclohexanes (α-, ß-, γ- and δ-hexachlorocyclohexane), dichlorodiphenyltrichloroethane including metabolites (o,p'- and p,p'-DDT, DDE and DDD), hexachlorobenzene, pentachlorobenzene, aldrin, dieldrin, endrins (endrin, endrin aldehyde and endrin ketone), isodrin, heptachlors (heptachlor, heptachlor epoxide A and heptachlor epoxide B), chlordanes (α-, ß-chlordane, oxychlordane and trans-nonachlor), endosulfans (α- and ß-endosulfan and endosulfan sulphate), methoxychlor and mirex using a gas chromatograph coupled to a mass spectrometer. The levels of OCPs ranged for the individual pesticides from below limit of quantification to 750 pg m(-3) (for α-endosulfan), and current agricultural application seemed to be the main primary source of most abundant pesticides. Re-volatilization of previously used pesticides from contaminated soils could not be ruled out either as potential secondary source of contamination, especially in warm and dry seasons and periods of intensive agricultural activities. Higher atmospheric concentrations were observed in November and December during the dry season compared to lower concentrations observed in June, July and August when the country experiences heavy rains. The highest seasonal variation was observed for currently used pesticides as α-endosulfan. A p,p'-DDT/p,p'-DDE ratio suggested recent inputs of fresh technical DDT.

Contamination levels and spatial distribution of organochlorine pesticides in soils from India.

Organochlorine pesticides, dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH), are potential chemical pollutants extensively used for agriculture and vector control purposes due to low cost and high effectiveness. Concentrations of HCH and DDT were determined in 175 surface soil samples from different agricultural fields, fallow and urban lands of districts Nagaon and Dibrugarh, Assam, India. The mean concentrations of total HCH and total DDT were 825 ng/g (range: 98-1945 ng/g) and 903 ng/g (range: 166-2288 ng/g) in district Nagaon while 705 ng/g (range: 178-1701 ng/g) and 757 ng/g (range: 75-2296 ng/g) in district Dibrugarh, respectively. The soils from paddy fields contained highest amounts of HCH and DDT residues. Total organic carbon was found to be positively associated with soil HCH and DDT residues. Ratios of DDT/(DDD+DDE) were 1.25 and 1.82 while of α/γ HCH were 2.78 and 2.51 for districts Dibrugarh and Nagaon, respectively. Source identification revealed that soil residue levels have originated from long past and recent mixed source of technical HCH and Lindane for HCHs and mainly technical DDT for DDTs. Spatial distribution was also investigated to identify the areas with higher pesticide loadings in soil.

Simultaneous determination of organochlorine pesticides and bisphenol A in edible marine biota by GC-MS.

A study to assess the level of organochlorine pesticides (OCPs) and bisphenol A (BPA) in edible marine biota collected from coastal waters of Malaysia was conducted using GC-MS and SPE extraction. An analytical method was developed and validated to measure the level of 15 OCPs and BPA simultaneously from five selected marine species. It was observed that some samples had low levels of p,p'-DDE, p,p'-DDT and p,p'- DDD ranging from 0.50 ng g(-1) to 22.49 ng g(-1) dry weight (d.w) but significantly elevated level of endosulfan I was detected in a stingray sample at 2880 ng g(-1) d.w. BPA was detected in 31 out of 57 samples with concentration ranging from below quantification level (LOQ: 3 ng g(-1)) to 729 ng g(-1) d.w. The presence of OCPs is most likely from past use although there is also indication of illegal use in recent times. The study also reveals that BPA is more widely distributed in coastal species caught off the coast of the most developed state. The potential health risk from dietary intakes of OCPs and BPA from the analysed fish species was negligible.

Analysis of pesticide residues using the Quick Easy Cheap Effective Rugged and Safe (QuEChERS) pesticide multiresidue method in traditional Chinese medicine by gas chromatography with electron capture detection.

The Quick Easy Cheap Effective Rugged and Safe multiresidue method (QuEChERS) has been validated for the extraction of 15 organochlorine pesticides (OCPs) in completely different matrices of traditional Chinese medicine (TCM). The method employed a rapid, simple and cost-effective procedure. The spiking levels for the recovery experiments were 0.1, 0.5 and 2.0 mg kg(-1). Mean recoveries mostly ranged between 76.0% and 114.0% (96.0% on average), and relative standard deviations (RSD) were generally below 10% (4.72% on average). Based on these results, the methodology has been proven to be highly efficient and robust and thus suitable for monitoring the MRL compliance of a wide range of commodity. The contamination status of 15 OCPs on 80 different TCMs marketed in China, and a total of 400 samples were also performed using a previously validated method. 15 OCPs were benzene hexachloride (BHC, including α-BHC, ß-BHC, γ-BHC, δ-BHC), hexachlorobenzene, heptachlor, heptachlor epoxide, aldrin, p, p'-DDE, p, p'-DDD, o, p'-DDT, p, p'-DDT, mirex, endrin, dieldrin. This study indicates that the proposed method is useful for analyzing OCPs in TCM.

Input pathways of organochlorine pesticides to typical freshwater cultured fish ponds of South China: hints for pollution control.

Air, rain, pond water, bank soil, pond sediment, fish feed, and fish were sampled from four freshwater cultured fish ponds (FWCFPs) in rural areas within the Pearl River Delta (PRD) of South China. Compositional analyses indicated that historical residues were the main sources of DDXs (defined as the sum of dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyldichloroethylene (DDE) and 1-chloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDMU)), and hexachlorocyclohexanes (HCHs) in the FWCFPs. The input fluxes to the FWCFPs were estimated at 4.0, 1.6, 15, and -0.92 µg/m(2) ·year for DDXs and 3.8, 0.92, 2.9, and -1.4 µg/m(2) ·year for HCHs for dry deposition, wet deposition, feeding, and net air-water exchange in Dongguan, and 3.8, 1.2, 137, and -1.2 µg/m(2) ·year for DDXs and 3.6, 0.66, 5.0, and -1.0 µg/m(2) ·year for HCHs in Shunde, respectively. These results indicated that fish feed was the dominant input source of DDXs to the FWCFPs. As for HCHs, fluxes via dry deposition and feeding were similar and slightly higher than those via wet deposition. Biological effects due to the occurrence of DDXs in the FWCFPs were minimal, and consumption of freshwater fish from the PRD appeared to pose insignificant risk to human health based on some existing regulations and guidelines.

Sequestration of organochlorine pesticides in soils of distinct organic carbon content.

In the present study, five soil samples with organic carbon contents ranging from 0.23% to 7.1% and aged with technical dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) for 15 months were incubated in a sealed chamber to investigate the dynamic changes of the OCP residues. The residues in the soils decreased over the incubation period and finally reached a plateau. Regression analysis showed that degradable fractions of OCPs were negatively correlated with soil organic carbon (SOC) except for α-HCH, while no correlation was found between degradation rate and SOC, which demonstrated that SOC content determines the OCP sequestration fraction in soil. Analysis of the ratio of DDT and its primary metabolites showed that, since it depends on differential sequestration among them, magnitude of (p,p'-DDE + p,p'-DDD)/p,p'-DDT is not a reliable criterion for the identification of new DDT sources.

Survey of organochlorine pesticides and polychlorinated biphenyls in commercial pasteurized milk in Iran.

The objective of this study was to investigate the presence of organochlorine pesticides (α-HCH, ß-HCH, γ-HCH, HCB, dieldrin, o,p'-DDE, p,p'-DDE, p,p'-DDD, p,p'-DDT) and polychlorinated biphenyl (PCBs) congeners (28, 52, 101, 138, 153, 180) in pasteurized and sterilized milk containing 1.5%, 2.5%, and 3% fat from Tehran province (Iran). Considering the importance of milk and dairy products for human nutrition and the toxicity of these compounds, their daily intake (DI) through milk was also determined. The compounds γ-HCH (13.49 ng g(-1) fat), ß-HCH (11.7 ng g(-1) fat), and PCB180 (7.56 ng g(-1) fat) were found at highest concentrations. The DI for all compounds was less than the acceptable daily intake established by FAO/WHO except for Σ PCBs which was more than the minimal risk level.

Distribution of organochlorine pesticides in sediments and mussels from the Istanbul Strait.

This study was conducted to determine the status and trends of organochlorine pesticide (OCP) compounds in the sediment and mussel samples collected along the Istanbul Strait and from the coasts of an island in the Marmara Sea. The total concentrations of OCPs were found in the range of 40-13,852 pg g(-1) dry weight for sediments and 5,195-12,322 pg g(-1) wet weight for mussels. The levels of OCPs in both sediments and mussels were dominated by DDTs and HCHs; ß-HCH, 4,4(')-DDD and 4,4(')-DDE were the major pollutants. The degree of sediment pesticide contamination was more severe in the inner part of the strait. OCP concentrations in sediments and mussels were compared with the sediment guideline values and legal limits for human health, respectively. The results showed that OC pesticide contamination in the strait might not pose a serious threat to the health of the marine inhabitants at most of the stations.

Bioaccumulation of organochlorine pesticides in aquatic system--an overview.

In recent years, various environmental issues have aroused a concern on the pollution of pesticides in rivers and in their various intercompartments. Multiple residues of pesticides discharged from industries or as a result of extensive use of agrochemicals in agriculture have been monitored. These pesticide residues contaminate the river ecosystem and its intercompartments such as sediments, and aquatic biota, and make it harmful to humans when they contaminate food and drinking water. The pesticide contamination in water, sediments, and aquatic biota has been reported to be beyond the acceptable range. The most commonly found pesticides are organochlorine, namely, dichlorodiphenyltrichloroethane, hexachlorocyclohexane, endosulfan, heptachlor, lindane, dieldrin, aldrin, endrin, and others. The paper discusses the general description, classification, and toxicity of pesticides; it also aims to create public awareness among people and appraise them with various alternate methods to combat the problem of pesticide contamination. An attempt has also been made to elucidate the findings of various works on pesticides in aquatic system and to highlight the challenging aspects of pesticide contamination, which have not attracted the attention of investigators yet.

Potential occupational exposures in the Reiss-Engelhorn-Museen Mannheim/Germany.

The Reiss-Engelhorn-Museen in Mannheim, Germany requested support from a toxicological laboratory in evaluating occupational exposures before a cleanup and renovation period in 2006. Samples of dust and dirt and scrapings of exhibits were collected from several locations. Following toxicologically relevant compounds could be identified by gas chromatography - mass spectrometry (GC/MS) by comparison with a mass spectra library: dichlorodiphenyl trichloroethane (DDT) and its breakdown product dichlorodiphenyl dichloroethane (DDD) as well as dichlorodiphenyl dichlorethylene (DDE), methoxychlor, nicotine, and camphor. In recent times various insecticides have been used to protect museum artefacts against moths, woodborers and other insect pests. Caution has to be made because the presence of hazardous compounds can result in security problems for museum staff as well as for visitors.

Analysis of pesticides and PCBs in waste wood and house dust.

The use of the pesticides - DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) and lindane (gamma-hexachlorocyclohexane) - and of PCBs (polychlorinated biphenyls) has been limited or forbidden for several decades. Nevertheless, due to their persistence and bioaccumulative potentials they are still ubiquitous in the environment. Therefore, the main objective of this study was to determine analytical methods to analyse the pesticides lindane and DDT, its metabolites DDD (1,1-dichloro-2,2-bis(4-chlorophenyl)ethane) and DDE (1,1-dichloro-2,2-bis(4-chlorophenyl)ethene), and PCBs in waste wood and house dust. An ultrasonic extraction was performed followed by a sample clean up by filtration or silica gel column. The prepared samples were measured by GC/MS. Quantification through internal standard calibration delivered low limits of detection. Specific amounts of the target compounds were detected in all analysed dust samples. The comparison of the contamination between dust samples of eastern Germany (former German Democratic Republic - GDR) and western Germany partly revealed significant differences of the contamination levels. Furthermore, it was examined whether older wooden material might cause a constant volatilisation of pesticides in apartments. Waste wood samples of different contamination categories were analysed. Apparently, these samples are potentially responsible for a constant DDX (Σ(DDT, DDD, DDE)) and lindane volatilisation, but not for PCBs.

Organochlorine pesticides in soils from south-western Uganda.

Organochlorine (OC) residues were analysed in soil samples collected from Kihiihi sub-county, Kanungu District, which is located in south-western Uganda. Mabira Central Forest Reserve which is located in central Uganda was used as a reference site in this study. The samples were collected at 15-20 cm depths below the soil surface and extracted with organic solvents. The extracts were cleaned using florisil, and were analysed using a gas chromatograph (GC) equipped with an electron capture detector (ECD). The results were confirmed using a GC equipped with a mass spectrometer (MS). The levels of the OC residues in soil from Kihiihi sub-county varied from non-detectable (ND) to 59 microg kg(-1) dry weight. The frequencies of detection for p,p'-DDT, p,p'-DDE and p,p'-DDD in the total soil samples were 47%, 24% and 11%, respectively. The o,p'compounds were detected in the following frequencies: o,p'-DDT (23%), o,p'-DDE (19%) and o,p'-DDD (8%). The low p,p'-DDE/p,p'-DDT residue ratios (0.2-0.9) in Kihiihi samples suggest recent inputs of DDT in Kihiihi sub-county. The detection frequencies for dieldrin, endosulfan-alpha, -beta and -sulphate in the soil samples were 21%, 26%, 31% and 19%, respectively. Mabira Forest Reserve soils showed detection frequencies of p,p'-DDT (5%) and p,p'-DDE (9% of the soil samples), varying from ND to 9 microg kg(-1). Although the use of OCPs has been banned, our results show that they can still be detected in the environment. Their presence may be attributed to adulteration of pesticides which are not banned and also atmospheric deposition.

Anaerobic biodegradation of organochlorine pesticides in contaminated soil - significance of temperature and availability.

Anaerobic biodegradation of the pesticides: gamma-hexachlorocyclohexane, methoxychlor, o,p'- and p,p'-DDT in field polluted soil was tested at 12, 22 and 30 degrees C, using methanogenic granular sludge as inoculum. The contaminants were removed quite effectively at all temperatures and their removal rates increased 1.2-1.7 times with the increase in temperature. In most cases pesticide concentrations after an initial substantial decline remained almost constant until the end of experiment. These residual concentrations were also temperature dependent and they were 1.4-8.2 times higher at 12 degrees C than at 30 degrees C. DDT was degraded via DDD and accumulation of this metabolite was lower (19-64%) than the corresponding amount of removed DDT, especially at higher temperatures. Further transformation of DDD was confirmed by formation of p,p'-dichlorobenzophenone. Additional experiment demonstrated that removal was limited to readily desorbing fractions of pesticides, while their desorption-resistant fractions persisted in the soil. However, DDD metabolite was only partially removed despite its good desorbability.

Triple domain in situ sorption modeling of organochlorine pesticides, polychlorobiphenyls, polyaromatic hydrocarbons, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans in aquatic sediments.

Here we analyze the potential of black carbon (BC) and oil-inclusive models to explain in situ sorption of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), organochlorine pesticides (OCP), polychlorobiphenyls (PCB), polyaromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDD), and polychlorinated dibenzofurans (PCDF) to harbor sediments. Such models are important to understand bioavailability and mobility limitations of these chemicals in the aquatic environment. Separate BC- or oil-inclusive models have been described before. However, it is unclear whether oil could dominate in situ sorption in sediments that also contain BC, and whether the relative importance of phases would differ for different compounds. A BC- and oil-inclusive model was evaluated against chemical data and measured sediment characteristics. Parameter uncertainty was assessed using Monte Carlo simulations. Fitted model parameters were consistent with literature data and were satisfactory from a statistical as well as a chemical perspective. Sorption to oil was strong, proportional to octanol-water partitioning (Log K(ow)) and of similar magnitude for OCP, PCB, PCDD, and PCDF. For PAH a single oil sorption coefficient was found. Oil dominated sorption only for PCBs, at oil levels above 50-250 mg oil/kg sediment. BC dominated sorption of most other compounds, especially high molecular PAHs, PCDD, and PCDFs.

Occurrence and distribution of organochlorine pesticides (OCPs) in surface sediments of the Bohai Sea, China.

Fifty-five surface sediment samples covering virtually the entire Bohai Sea (Bohai) were analyzed for organochlorine pesticides (OCPs), in order to provide the extensive information of recent occurrence levels, distribution, possible sources and potential biological risk of these compounds in this area. Concentrations of total dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) in Bohai ranged widely from 0.24 to 5.67ngg(-1) (mean 1.36+/-0.93ngg(-1)) and 0.16 to 3.17ngg(-1) (mean 0.83+/-0.57ngg(-1)), respectively. High concentrations of DDTs were observed in the coastal areas especially at the isolated sites neighboring the harbor or port regions. The recent DDT inputs could be mainly attributed to the agricultural activity (e.g. dicofol), wastewater of chemical plants and the usage of antifouling paint. The distribution pattern of HCHs was different from that of DDTs due to their different physical-chemical properties and amounts of production and usage in the past. (DDE+DDD)/DDT ratios indicated that the degradation of the parent DDT occurred significantly. The contributions of previous and current inputs of pesticides in the coastal areas were distinguished by means of principal component analysis, suggesting that the recent usage of DDT and technical chlordane could serve as important fresh input sources for OCPs. DDTs and chlordanes are the two-main species of OCPs with more ecotoxicological concern in Bohai.