Studies on the distribution op β‐ and γ‐isombrs op hexachlorocyclohexane in rat tissues

Abstract

A study of the comparitlve distribution pattern of β‐ and γ‐isomers of hexachlorocyclohexane (HCH) in albino rat tissues as a function of duration of treatment at two dose levels revealed different accumulation patterns for the two isomers in tissues. In general, the accumulation pattern was found to be in the order: fat > kidney > lungs > liver > muscle > heart > spleen > brain > blood for β‐HCH and fat > brain > kidney > muscle > lungs > heart > spleen > liver > blood for γ‐HCH. The tissue accumulation of β‐isomer was always greater than that of γ‐isomer in any tissue except in brain. Brain β‐HCH residue levels were relatively lower than in many other tissues except blood, whereas brain γ‐HCH concentration was only next to fat. A higher dose or a longer period of treatment generally produced a more marked elevation of tissue residue levels in β‐HCH fed rats, but not in γ‐HCH treated animals.

Food restriction subsequent to a period of exposure to dietary β‐ or γ‐HCH caused a mobilization of depot fat without drastic redistribution of the HCH residues stored in it. During food restriction, the residue levels in fat and muscle increased much. The residue levels in brain and other organs were not adversely affected during partial starvation.     

Effect of maternal dietary hexachlorocyclohexane exposure on pup survival and growth in albino rats

Abstract

In adult albino rats, maternal dietary. ß‐ and ?‐hexachlorocyclohexane (HCH) intake during gestation upto 400 ppm level did not affect the number of litters produced. But about 50 and 100% pup mortality was found in 200 and 400 ppm ß ‐HCH group within 5 days of birth. Maternal mortality was observed in 800 ppm ß ‐HCH group during third week of gestation. The effect of maternal dietary intake of HCH isomers at 50 and 250 ppm level during gestation and/or lactation on perinatal development was also studied. The body weights and sizes of the newborn litters of mother rats exposed to dietary HCH isomers did not. differ from controls. Similarly, the growth and development of the litters of HCH exposed mother rats that survived 28 day lactation period were found to be comparable to controls as evidenced by the body weight and weight of vital organs. However, liver weight increases were found in the 28 day weaned litters wherever the mothers had been exposed to HCH isomers during lactation. Lowered kidney weight was seen in litters of mother rats fed 250 ppm ?‐HCH during gestation and lactation. The brain and testis weights were not affected in the litters of any experimental groups.     

Occurrence and distribution of hexachlorocyclohexane isomers in vegetation samples from a contaminated area

The occurrence and distribution of four major hexachlorocyclohexane (HCH) isomers (alpha-, beta-, gamma- and delta-) were studied in vegetation samples of a highly contaminated area close to a small-scale industrial belt in Lucknow (North India). Eight species of plants were collected at different points of the contaminated area and different parts of the plants were separated in order to study the difference in uptake and accumulation. The samples were extracted by matrix solid-phase dispersion (MSPD) extraction and finally determined by a gas-chromatograph equipped with (63)Ni electron capture detector (ECD). HCH isomers were present in almost all samples and the concentration of total HCH in the plant sample analyzed varied between 13 and 44 mg kg(-1), being the main isomer of beta-HCH (8-22 mg kg(-1)). Lindane (gamma-HCH) was present in all samples (1-9 mg kg(-1)). Solanum torvum Sw., and Erianthus munja shows the highest and lowest capacity for accumulation of HCH, respectively with a significant difference at p<0.01 level. The highest concentration of HCH residue in root samples indicates the most likely mechanism of HCH accumulation in these plants was sorption of soil HCH on roots. Solanum torvum Sw., and Withania somnifera (L.) Dunal could accumulate considerable levels of HCH isomers (44 and 34 mg kg(-1), respectively). The results reflect the importance of plants in monitoring purposes and their potential for phytoremediation of HCH contaminated soils.     

Behaviour of alpha-, beta-, gamma-, and delta-hexachlorocyclohexane in the soil-plant system of a contaminated site

The behaviour of the organochlorine pesticide hexachlorocyclohexane (HCH) is investigated. The concentrations of alpha-, beta-, gamma-, and delta-HCH isomers were measured in soils, rhizosphere and vegetation in a contaminated area in Galicia (NW Spain). The total concentration of HCH in soils reached values close to 20,000 mgkg(-1). The plants analysed (Avena sativa L., Chenopodium spp., Solanum nigrum L., Cytisus striatus (Hill) Roth, and Vicia sativa L.) accumulated HCH, especially the beta-HCH isomer, in their tissues. The most likely mechanisms of HCH accumulation in plants were sorption of soil HCH on roots and sorption of volatilized HCH on aerial plant tissues. The concentrations of HCH obtained from the bulk and rhizosphere soils of selected plant species suggest that roots tend to reduce levels of the HCH isomers in the rhizosphere. The results reflect the importance of vegetation in the distribution of organochlorine compounds in the soil-plant system.     

Distribution of hexachlorocyclohexane isomers in soil samples from a small scale industrial area of Lucknow, North India, associated with lindane production

Concentrations of hexachlorocyclohexane isomers (alpha-HCH, beta-HCH, gamma-HCH, and delta-HCH) were studied in soils samples collected from a small scale industrial unit of Lucknow associated with lindane production. All four isomers were detected from ten sites and the total HCH isomers in the analyzed samples varied from 53 to 99mgkg(-1). Cluster analysis was performed to group the soil sites in terms of their HCH contamination level. Low alpha/gamma HCH ratios were found and they indicate recent input of HCH. There is an urgent need for the on-site remediation of these contaminated sites in order to prevent the long-term environmental pollution.     

Distribution pathways of hexachlorocyclohexane isomers in a soil-plant-air system. A case study with Cynara scolymus L. and Erica sp. plants grown in a contaminated site

This study focuses on the main routes of distribution and accumulation of different hexachlorocyclohexane (HCH) isomers (mainly α-, β-, γ- and δ-HCH) in a soil-plant-air system. A field assay was carried out with two plant species, Cynara scolymus L. and Erica sp., which were planted either: (i) directly in the HCH-contaminated soil; or (ii) in pots filled with uncontaminated soil, which were placed in the HCH-contaminated soil. Both plant species accumulated HCH in their tissues, with relatively higher accumulation in above-ground biomass than in roots. The β-HCH isomer was the main isomer in all plant tissues. Adsorption of HCH by the roots from contaminated soil (soil → root pathway) and adsorption through the aerial biomass from either the surrounding air, following volatilization of the contaminant (soil → air → shoot pathway), and/or contact with air-suspended particles contaminated with HCH (soil particles → shoot pathway) were the main mechanisms of accumulation. These results may have important implications for the use of plants for reducing the transfer of contaminants via the atmosphere.     

Biodegradation of α and β isomers of endosulphan and endosulphan sulphate in Indian soils

Abstract

The degradation of α and β isomers of endosulphan and endosulphan sulphate in four sterilized and non sterilized Indian soils under laboratory conditions was studied. Degradation was found to be more in non‐sterilized as compared to the sterilized soil. The half life of α‐endosulphan, β‐endosulphan and endosulphan sulphate was found to be 136.8, 273 and 301 days in sterilized Alfisol and 55, 256 and 277 days in non‐sterilized Alfisol, respectively. α‐Endosulphan degraded more readily than β‐endosulphan and endosulphan sulphate under both sterilized and non‐sterilized soil conditions.     

Role of vitamin A in the haematotoxicity of hexachlorocyclohexane (HCH) in the rat.

The haematotoxicity of technical hexachlorocyclohexane (HCH) (1000 ppm) was investigated in male albino rats fed with diet free of vitamin A or containing vitamin A at 2000 or 10(5) I.U./kg. Assessment of HCH-induced haematotoxicity at the end of the 7 weeks feeding period was done on the basis of haemoglobin content, total count of red blood cells and white blood cells and the differential counts of the white blood cells as well as by parameters such as packed cell volume, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin content, prothrombin time and clotting time. In the rats fed with vitamin A-free diet containing HCH, significant reductions were noticed in the total white blood cells count, clotting time and prothrombin time indicating severe haematotoxicity. Differential count of the white blood cells of these rats revealed a non-significant reduction in the lymphocyte count. The only indication of haematotoxicity caused by hexachlorocyclohexane in the vitamin A supplemented rats was a slight but statistically significant reduction of the total count of white blood cells. These results demonstrate that the haematotoxicity of hexachlorocyclohexane in the rats is enhanced by vitamin A-deficiency and its supplementation particularly in excess but not at hypervitaminotic level is protective against the toxicity.     

Geostatistical analysis and kriging of Hexachlorocyclohexane residues in topsoil from Tianjin, China

A previously published data set of HCH isomer concentrations in topsoil samples from Tianjin, China, was subjected to geospatial analysis. Semivariograms were calculated and modeled using geostatistical techniques. Parameters of semivariogram models were analyzed and compared for four HCH isomers. Two-dimensional ordinary block kriging was applied to HCH isomers data set for mapping purposes. Dot maps and gray-scaled raster maps of HCH concentrations were presented based on kriging results. The appropriateness of the kriging procedure for mapping purposes was evaluated based on the kriging errors and kriging variances. It was found that ordinary block kriging can be applied to interpolate HCH concentrations in Tianjin topsoil with acceptable accuracy for mapping purposes.     

Renal tubular dysfunction caused by dietary hexachlorocyclohexane (HCH) isomers

Abstract

Dietary administration of β‐ and α‐hexachlorocyclohexane (HCH) to albino rats caused an abnormal excessive excretion of glucose in the urine, blood glucose level being nearly normal. Occurrence of glucosuria was also accompanied by increased excretions of the two low‐threshold compounds ‐ creatinine and urea, their levels in blood being normal. The interference of HCH isomers with renal function as evidenced by biochemical data was also indicated by histopathological lesions observed in the kidney sections, viz., hypertrophy and degeneration of the renal tubular epithelia.     

Application of a level IV fugacity model to simulate the long-term fate of hexachlorocyclohexane isomers in the lower reach of Yellow River basin, China

A level IV multimedia fugacity model was established to simulate the fate and transfer of hexachlorocyclohexane (HCH) isomers in the lower reach of the Yellow River basin, China, during 1952-2010. The predicted concentrations of HCHs are in good agreement with the observed ones, as indicated by the residual errors being generally lower than 0.5 logarithmic units. The effects of extensive agricultural application and subsequent prohibition of HCHs are reflected by the temporal variation of HCHs predicted by the model. It is predicted that only 1.8 tons of HCHs will be left in 2010, less than 0.06% of the highest contents (in 1983) in the study area, and about 99% of HCHs remain in soil. The proportions of HCH isomers in the environment also changed with time due to their different physicochemical properties. Although beta-HCH is not the main component of the technical HCHs, it has become the most abundant isomer in the environment because of its persistence. The dominant transfer processes between the adjacent compartments were deposition from air to soil, air diffusion through the air-water interface and runoff from soil to water. Sensitivity analysis showed that degradation rate in soil, parameters related to major sources, and thickness of soils had the strongest influence on the model result. Results of Monte Carlo simulation indicated the overall uncertainty of model predictions, and the coefficients of variation of the estimated concentrations of HCHs in all the compartments ranged from 0.5 to 5.8.     

Long-term atmospheric deposition of current-use and banned pesticides in Atlantic Canada; 1980-2000

The occurrence of current-use and banned pesticides is reported in wet-precipitation collected from four sites across Atlantic Canada during the period 1980-2000. The most frequently detected compounds were alpha-HCH, gamma-HCH (lindane), chlorothalonil, pentachlorophenol, atrazine, and endosulfan. Median site concentrations varied between not-detected and 10.2 ng l(-1). Deposition of HCHs (hexachlorocyclohexane), chlorothalonil, and endosulfan at Kejimkujik (Keji) and Jackson, Nova Scotia, were generally similar. Significant spatial differences (p<0.05), however, were found for the HCH isomers and endosulfan at Keji and Gros Morne (Newfoundland and Labrador), areas geographically separated by the northern Gulf of St. Lawrence. Long-term deposition of alpha-HCH decreased (p<0.05) at both Keji (1980-2000) and Gros Morne (1994-2000), with half-lives of 5.9 and 4.5 y, respectively. A decreasing trend was also found for pentachlorophenol with a half-life of 4.9 y at Jackson. Significant negative trends (p<0.05) were observed for alpha-/gamma-HCH ratios during the study at Keji and Jackson, possibly reflecting changes in production and use patterns of technical HCH and lindane on a continental and perhaps hemispheric scale. Seasonal trends for alpha-HCH and gamma-HCH were found to vary over the 20-y study period at Keji, however, spatial trends were generally similar between sites. Seasonal trends were observed with peak deposition generally occurring during the growing period (spring-summer) for the HCHs, chlorothalonil, endosulfan, and atrazine. Bimodal seasonal trends were also observed for these compounds with the exception of endosulfan.     

Hair analysis: another approach for the assessment of human exposure to selected persistent organochlorine pollutants

Hair analysis was used for the assessment of exposure to organochlorine pollutants in specimens from Greece, Romania and Belgium. A simple method (using 3 N HCI as incubation reagent, liquid-liquid extraction with hexane/ dichloromethane (DCM), alumina/acid silica clean-up and GC-ECD/GC-MS analysis) was used for screening of specimens. The highest organochlorine load (up to 148 ng/g hair for the sum of PCB, DDT and hexachlorocyclohexane (HCH) isomers) was found in samples from a group of Greek women with past occupational exposure to pesticides. DDTs were the main organochlorine pollutants in Greek samples (up to 70%), while in Belgian hair samples their contribution was reduced to 40%. PCB mean concentration was higher in Belgian specimens (up to 14 ng/g hair). Lindane (y-HCH) was the main HCH isomer found in the samples (up to 82% in the Greek samples). Contribution of p,p'-DDT to the sum of DDTs was higher in Greek samples and indicates recent exposure to technical DDT. Similar PCB 153/sum PCBs ratios were found for each of the three countries suggesting similar sources of pollution with PCBs (mainly dietary). Artificially coloured hair samples were found to have lower, but not statistically significant concentrations of organochlorine pollutants than the non-coloured hair.     

POP-contaminated sites from HCH production in Sabiñánigo, Spain

In 2009, hexachlorocyclohexane (HCH) isomers (α-HCH, β-HCH, and γ-HCH [lindane]) were listed as persistent organic pollutants (POP) in the Stockholm Convention. Accordingly, the legacy of HCH/lindane production with the associated large HCH waste deposits has become recognized as an issue of global concern and is addressed in the implementation of the Convention. The current paper gives an overview of the major contaminated sites from lindane production of the INQUINOSA Company. This company operated from 1975 to 1988 in the city of Sabiñánigo, Spain. HCH production resulted in the production of approximately 115,000 tonnes of waste isomers which were mainly dumped in two unlined landfills. These two landfill sites, together with the former production site, are recognized sources of environmental pollution. Assessment and remediation activities at these sites are described. A dense nonaqueous phase liquid (DNAPL) contaminated inter alia with HCH isomers, benzene, chlorobenzenes, and chlorophenols as the main contaminants and an associated contaminated groundwater plume have been discovered at both landfill/dumpsites and at the former production site. The approximately 4,000 t of DNAPLs constitute a serious risk for the environment due to the proximity of the Gállego River. Since 2004, more than 20 tonnes of this DNAPL has been extracted using “pump and treat” techniques. The Aragon Regional Government and the Spanish Environmental Ministry are taking action, focusing on the treatment of DNAPL and on the transfer of the large quantities of solid POP wastes to a new landfill. A range of laboratory tests has been performed in order to plan the aquifer remediation.     

Organochlorine pesticides accumulation and degradation products in vegetation samples of a contaminated area in Galicia (NW Spain)

The content of 21 organochlorine pesticides were studied in vegetation samples of a highly contaminated area by isomers of hexachlorocyclohexane (HCH) located close to a former industrial area in Galicia (NW Spain). Five species of plants were collected at different points of the contaminated area and the different parts of the plants were separated in order to study differences in accumulation capabilities. Samples were extracted employing microwave energy followed by a clean-up step using solid phase extraction and finally determined by GC–ECD. The results obtained show that the most abundant pesticides are HCHs isomers, being the main isomers β-HCH and -HCH in all samples whereas δ-HCH and γ-HCH were at lower levels. Some other pesticides such as p,p′-DDT, p,p′-DDD and p,p′-DDE were also present in much lower amount in some of the samples. Several degradation products of HCH were also identified in some samples by GC–MS.     

Residues of organochlorine pesticides,polychlorinated biphenyls and heavy metals in the eggs of predatory birds from Doñana National Park (Spain), 1980–1983

Abstract

Organochlorine pesticides and heavy metal residues were determined in 54 eggs of five species of predatory birds collected at Doñana National Park (Spain) during the nesting season between 1980 and 1983. The species analyzed were the imperial eagle (Aquila heliaca), the red kite (Milvus milvus), the black kite (Milvus migrans), the hobby (Falco subbuteo) and the booted eagle (Hieraetus pennatus). DDE, DDT and PCBs were detected in all samples. α‐HCH, α‐HCH, aldrin, dieldrin, heptachlor, heptachlor epoxide, TDE and dichlorobenzophenone were also detected but less frequently. The DDE content of eggs decreased in the period between 1972/1976 and 1980/1983, but the PCBs contents were stable. The declines are attributed to the restrictions on the use of DDT in most countries. Mercury, lead, cadmium, copper and zinc were detected in all samples. The levels of organochlorine pesticides, PCBs and heavy metals in these Falconiforme eggs are generally below the levels known to cause direct effects on survival or reproduction of birds.     

Evaluation of hexachlorocyclohexane contamination from the last lindane production plant operating in India

Purpose

??-Hexachlorocyclohexane (HCH), ??-HCH, and lindane (??-HCH) were listed as persistent organic pollutants by the Stockholm Convention in 2009 and hence must be phased out and their wastes/stockpiles eliminated. At the last operating lindane manufacturing unit, we conducted a preliminary evaluation of HCH contamination levels in soil and water samples collected around the production area and the vicinity of a major dumpsite to inform the design of processes for an appropriate implementation of the Convention.

Methods

Soil and water samples on and around the production site and a major waste dumpsite were measured for HCH levels.

Results

All soil samples taken at the lindane production facility and dumpsite and in their vicinity were contaminated with an isomer pattern characteristic of HCH production waste. At the dumpsite surface samples contained up to 450?g?kg^?1 ?? HCH suggesting that the waste HCH isomers were simply dumped at this location. Ground water in the vicinity and river water was found to be contaminated with 0.2 to 0.4?mg?l^?1 of HCH waste isomers. The total quantity of deposited HCH wastes from the lindane production unit was estimated at between 36,000 and 54,000?t.

Conclusions

The contamination levels in ground and river water suggest significant run-off from the dumped HCH wastes and contamination of drinking water resources. The extent of dumping urgently needs to be assessed regarding the risks to human and ecosystem health. A plan for securing the waste isomers needs to be developed and implemented together with a plan for their final elimination. As part of the assessment, any polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) generated during HCH recycling operations need to be monitored.     

Biochemical changes produced by beta- and gamma-hexachlorocyclohexane isomers in albino rats

Administration of beta- and gamma-isomers of hexachlorocyclohexane (HCH) at 800 ppm dietary level for 2 weeks to albino rats produced noticeable hepatocellular damage as indicated by elevations in serum aminotransferases and decreases in hepatic soluble enzymes. Although serum total LDH activity was not altered, the LD5 isoenzyme was proportionately higher in the HCH isomers treated animals. Treatment of rats with beta- and gamma-isomers of HCH increased the hepatic glucose-6-phosphate dehydrogenase and aldolase activities suggesting a higher rate of glucose oxidation. Liver glucose-6-phosphatase activity was decreased in these animals indicating inactivation of gluconeogenesis in liver. Dietary beta- and gamma-HCH decreased the liver mitochondrial DNP/Mg++/Ca++-activated ATPases thus affecting the energy metabolism. An unaltered ratio of DNP/Mg++-ATPase, a study of swelling pattern of hepatic mitochondria, and NAD+ permeability test suggested the maintenance of structural integrity of mitochondrial membrane in these pesticide fed animals. Liver microsomal Na+,K+-ATPases were lower in these animals.     

Seasonal variation of persistent organochlorine insecticide residues in Vellar River waters in Tamil Nadu, South India

Water samples collected from Vellar river and Pichavaran mangroves at Porto Novo (11 degrees 29' N, 79 degrees 46' E), Tamil Nadu State, South India, from December 1987 to January 1989 were analyzed to determine the seasonal variation of the levels of organochlorine insecticides such as HCH (BHC) and DDT. Both these insecticides showed higher levels from October to February, although this trend was more pronounced in HCH than DDT, reflecting the application of technical HCH largely and probably small quantities of DDT during the flowering season of rice. The alpha-HCH was detected as a dominant isomer for all seasons monitored followed by beta-HCH. Among DDT compounds, p,p'-DDT was the highest in river water except in the dry season when p,p'-DDD showed a higher percentage. On the other hand, in mangroves p,p'-DDE was highest during the wet season and p,p'-DDD during the dry season. Air-water partitioning data of HCH isomers and DDT compounds in Vellar river revealed that these chemicals tend to be in the water phase. These observations may aid in understanding the role of a tropical paddy area on the behavior and fate of man-made chemicals in view of worldwide contamination.     

An anaerobic bioreactor allows the efficient degradation of HCH isomers in soil slurry

The insecticide gamma-hexachlorocyclohexane (gamma-HCH or lindane), which has been extensively used for agricultural and medical purposes, presents high persistence and toxicity to the environment and low solubility. This study intends to assess the efficiency of an anaerobic reactor to degrade HCH isomers contained in soil slurry cultures. This study was developed in two phases: experiments in flasks to optimize the process parameters, and assessment of the slurry process in the anaerobic slurry reactor operated for an approximate period of a year. The influence of different environmental conditions was evaluated: the HCH concentration (25-100 mg HCH kg-1), the type of substrate (volatile fatty acids or starch), the sludge concentration (2-8 g VSS l-1) and the replacement of spiked soil to simulate a fed-batch operation (10-50%). The best results were obtained when the reactor was operated with a sludge concentration of 8 g VSS l-1, starch concentration of 2 g COD l-1 and soil replacements of 10-20%. Under these conditions, alpha- and gamma-HCH were completely degraded after 10d while nearly 90% beta- and delta-HCH were removed only after 50 d. According to the obtained results related to the total degradation of the HCH isomers and the degradation rates, especially high for alpha- and gamma-HCH, the anaerobic slurry reactor appears to be a good alternative for the degradation of the HCH isomers present in polluted soil.