Mean Concentrations Of DDT Research Articles

Pilot study on the concentrations of organochlorine compounds and potentially toxic elements in pregnant women and local food items from the Finnish Lapland

In the Arctic, main sources of persistent organic pollutants and potentially toxic elements are industry and agriculture in the lower latitudes. However, there are also local sources of pollution. Our study was focused on possible pollution in the Finnish Lapland, transferred from the Pechenganikel industrial complex located in the borders of Russia, Finland and Norway.Local food items and blood samples of pregnant women from the Inari municipality were collected and organochlorine compounds (OCs) and metal(oid)s analyzed. Most of the examined food samples showed detectable levels of these compounds. The mean concentrations of DDTs and polychlorobiphenyls (PCBs) were higher in fish (0.18–0.32 ng/g and 0.34–0.64 ng/g, respectively), than in the other food groups (0.027–0.047 ng/g and 0.11–0.20 ng/g, respectively).PCBs were found at the highest concentrations in blood samples of the pregnant women, and congeners 153 and 118 were dominant. The mean concentration of PCB153, 0.29 μg/kg serum lipid, was lower than those described in many other studies. Concerning DDTs, the 4,4′-DDT/4,4′-DDE ratio, 0.092, in the blood samples was lower than that observed in the food items, 0.25–0.71, reflecting old uses of the DDT pesticide. None of the observed levels of selected potentially toxic elements in blood samples and in food items exceeded the known safe limits.Higher concentrations of PCB52 and γ-HCH were observed in the serum of pregnant women who consumed greater amounts of meat, and berries and mushrooms, respectively. The OC concentrations from the pregnant women currently studied were lower than those observed fourteen years ago with pregnant women from the same municipality. Compounds whose occurrence is likely related to a long-distance transport showed clear decreases, e.g., 63% for PCBs, and for those from pesticides, decreases were 93% and 97% for 4,4′-DDE and β-HCH, respectively. No obvious influence from the Pechenganikel complex is observed from the results.

Dissipation of organochlorine insecticide residues in the environment of Taiwan, 1973-1999

Organochlorine insecticides were used in Taiwan for agricultural and public health purposes mainly from 1950 to 1974. In this study, various survey and analysis studies on soil, water, sediment and animals from 1973 to 1999 were compared, temporal trends were analyzed, and the significance was discussed. In 1973, DDT, DDE, DDD, dieldrin, lindane and aldrin were the major organochlorine insecticides found at higher levels in rice paddy soil in Taiwan. In 1981, average total DDTs concentration of surface soil decreased to one-third of the 1973 level. Subsequently in 1994, total DDTs concentration in surface soil again decreased to one-third of the 1981 level. Dieldrin, lindane and aldrin concentrations decreased even faster and were much lower compared to DDT since 1981. Organochlorine insecticide mean concentrations in river water had reached ppt levels from 1973-1976, but were rarely detected in the 1990s. River sediment concentrations showed a rapid decrease from 1973 to 1976, but although there were variations among different rivers in Taiwan, sediment concentrations of lindane, DDT, DDE and aldrin reached a few ppb and were higher in 1981 compared to 1973-1976 on average. In recent years, total organochlorine insecticide concentration decreased to the ppb level, with most individual insecticide concentrations below 1 ppb. Shellfish organochlorine pesticide concentrations were slightly higher than sediment, and shellfish DDT, DDE, aldrin, dieldrin concentrations also showed an increase from 1973 to 1983 on average. The mean concentrations of DDT and aldrin were higher than 10 ppb in shellfish in 1983 and decreased to below the ppb level in the 1990s. Fish muscle contained ppb levels of organochlorine insecticides in 1973. In recent years, most of the organochlorine insecticide concentrations in shellfish and fish were less than 1 ppb except DDE. Duck eggs and human milk had been found to contain sub ppm levels of DDT and DDE in the 1970s and 1980s, but there was few recent data available. Although organochlorine insecticide levels in the environment of Taiwan have fallen fast over the last 26 years, DDTs and other organochlorine insecticide residue levels in higher animals should be determined for their bioaccumulation potential through the food chain.

Risk assessment of endocrine-disrupting pesticides exposure through consumption of Carassius auratus collected from Qiantang River, China

Data on the presence and distribution of endocrine-disrupting pesticides (EDPs) in aquatic environments and biota are important for ecological and human health risk assessment. Compared with that in developed countries, little attention has been paid on environmental EDPs pollution in developing countries including China. Thus, the EDPs in carps (Carassius auratus) from Qiantang River in China were investigated to assess the potential human health hazards of these contaminants. Among the EDPs, hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) were found in C. auratus. The mean concentrations of DDTs (7.71 ± 6.46 µg/kg ww) were 1–2 orders of magnitude higher than those of HCHs (0.17 ± 0.25 µg/kg ww), which could be attributed to the extension utilization in history and high lipophilicity of DDTs. Although the highest concentrations of ΣHCHs and ΣDDTs in analyzed samples were lower than the corresponding maximum limits set by Chinese authorities, the estimated daily intake was less than 1% of the acceptable daily intake and the hazard ratio value was below 1 × 10−4. It could be concluded that consumption of C. auratus from Qiantang River posed low health risk of EDPs exposure.

Contamination of Omnivorous Freshwater Fish Species and Sediments by Chlorinated Hydrocarbons in Poland

Abstract The occurrence and concentrations of organochlorine pesticides and polychlorinated biphenyls (PCBs) were determined in 158 muscle samples of bream (Abramis brama) and roach (Rutilus rutilus), and 84 samples of sediments collected from 10 river and lake sampling sites in 2011 and 2012. The concentrations of DDTs (p,p’-DDT, o,p’-DDT, p,p’-DDE, and p,p’-DDD), HCH isomers (a-, ß-, and y-HCH), HCB, and PCBs (six indicator PCB congeners 28, 52, 101, 138, 153 and 180) were determined using the capillary gas chromatography. The mean concentrations of DDTs in bream and roach were in the range of 11.2-654 and 4.5-121 ug/kg wet weight respectively, and PCBs were in the range of 1.3-75.9 and 1.1-112 ug/kg wet weight, respectively. Mean concentrations of DDTs and PCBs in sediments were 0.5-270 ug/kg dry weight and ⋋0.1-2.2 ug/kg dry weight respectively. The study showed clear spatial differences in the levels of organochlorine pesticides and PCBs in fish and sediments from different aquatic ecosystems. The highest levels of contaminants were detected in fish and sediments from the Vistula River in vicinity of Cracow. The possible risk to the fish meat consumers and ecological risk were evaluated.

Atmospheric deposition of persistent organic pollutants to the East Rongbuk Glacier in the Himalayas

To assess levels and seasonal trends of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in a high-altitude mountain region, a 2.1 m snowpack sample was collected from the East Rongbuk Glacier at 6572 ma.s.l. on Mt. Everest in September 2005. This snowpack covered a full year period from the fall of 2004 to the summer of 2005 and reflected the major meteorology of the monsoon and non-monsoon seasons. The most abundant compounds detected in the snow samples were γ-hexachlorocyclohexane (γ-HCH) and α-HCH with mean concentrations of 123 pg L − 1 and 92 pg L − 1 , respectively. This is the first detection of these compounds in recent snow samples from the Himalayas. Backward air trajectory analysis indicated that the Himalayas could be influenced by the major HCH source regions in both India and China. Among the seven marker PCB congeners (PCB 28, 52, 101, 118, 138, 153, and 180) quantified, PCB 28 and PCB 52 were the only dominant PCB congeners detected, with mean concentrations of 17 pg L − 1 and 6 pg L − 1 , respectively. In addition, DDT metabolites, p,p′-DDE and p,p′-DDD were detected in some snow samples and mean concentrations of DDTs were 24 pg L − 1 . Seasonal differences were observed for α- and γ-HCH concentrations increasing from the non-monsoon season to the monsoon season. Meanwhile, PCB 28 and HCB showed uniform variations with peak concentrations resulting from an effective scavenging by snowfalls between the monsoon and non-monsoon interval. Compared to other high mountain areas, the levels of POPs deposited into the East Rongbuk Glacier were relatively low, resulting from the highest altitude and remoteness from source regions.

Determination of DDT and Metabolites in Surface Water and Sediment Using LLE, SPE, ACE and SE

Surface water and sediment samples collected from Jukskei River in South Africa, were subjected to different extraction techniques, liquid-liquid (LLE), solid-phase extraction (SPE), activated carbon extraction (ACE) and soxhlet extraction (SE) for sediment. The samples were extracted with dichloromethane, cleaned in a silica gel column and the extracts quantified using a Varian 3800 GC-ECD. The percentage recovery test for 2,4'DDT, DDE and DDD and 4,4'DDT, DDE and DDD in water ranged from 80%-96% and 76%-95% (LLE); 56%-76% and 56%-70% (SPE) and 75%-84% (ACE), respectively; while that recoveries for sediment samples varied from 65%-95% for 2,4'DDT, DDE and DDD and 80%-91% for 4,4'DDT, DDE and DDD. The high recoveries exhibited by ACE compared very well with LLE and SE. This was not the case with SPE which exhibited the lowest value of recoveries for both 2,4 and 4,4'DDD, DDE and DDT standard samples. The mean concentrations of DDT and metabolites ranged from nd-1.10 μg/L, nd-0.80 μg/L, nd-1.21 μg/L and 1.92 μg/L for LLE, SPE, ACE and SE, respectively. The total DDT (2,4' and 4,4'-DDT) in water and sediment samples ranged from 1.20-3.25 μg/L and 1.82-5.24 μg/L, respectively. The low concentrations of the DDT metabolites obtained in the present study may suggest a recent contamination of the river by DDT.

Organochlorine pesticide and polychlorinated biphenyl residues in feathers of birds from different trophic levels of South-West Iran

Persistent organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), α, β and γ-hexachlorocyclohexane (HCH) isomers, together with polychlorinated biphenyl (PCB) congeners (IUPAC Nos. 28, 52, 101, 138, 153 and 180), were determined in tail feathers from 37 birds belonging to 18 species, all originating from the South-West of Iran (Khuzestan, coast of the Persian Gulf). This is the first report on organochlorine contaminants in feathers from museum collections and it is an indication of the concentrations of OCPs and PCBs in the past (1991–1996). Median concentrations of HCHs, DDTs, PCBs and HCB were 22, 14, 11 and 10 ng/g feather, respectively. Significant correlations ( p < 0.05) were calculated between OCPs (except HCB) and PCBs in the bird feathers. p, p′-DDE and γ-HCH were the most abundant OCPs, while CB 180, CB 138 and CB 101 were the predominant PCB congeners in almost all species. Significant differences ( p < 0.05) in the mean concentrations of DDTs and PCBs were detected among species grouped according to their feeding habits. Levels of DDTs and PCBs were highest in the carnivorous species and lowest in the herbivorous species. Levels of OCPs and PCBs in feathers of bids in the 1990s were generally below the thresholds reported to affect reproduction.

Persistent organochlorine pesticide residues in fish, sediments and water from Lake Bosomtwi, Ghana

Some organochlorine pesticide residues in tilapia fish ( Tilapia zilli), sediment and water samples from Lake Bosomtwi (the largest natural lake in Ghana) were determined to find out the extent of pesticide contamination and accumulation in the lake. The extracted residues were analyzed on a micro-capillary gas chromatograph equipped with electron capture detector. DDE ( p, p′-1,1-dichloro-2,2-bis-(4-chlorophenyl)ethylene) was the predominant residue in all the samples analyzed; detected in 82% of water samples, 98% of sediment samples and 58% of fish samples at concentrations of 0.061 ± 0.03 ng g −1, 8.342 ± 2.96 ng g −1 and 5.232 ± 1.30 ng g −1, respectively. DDT ( p, p′-1,1,1-trichloro-2,2-bis-(4-chlorophenyl)ethane) was detected in 78% at a mean concentration 0.012 ± 0.62 ng g −1 of water samples analyzed. The mean concentrations of DDT in sediments and fish were 4.41 ± 1.54 ng g −1 and 3.645 ± 1.81 ng g −1, respectively. The detection of lower levels of DDT than its metabolite, DDE, in the samples implies that the presence of these contaminants in the lake is as result of past usage of the pesticides.

Levels of persistent organic pollutants in air in China and over the Yellow Sea

The occurrence of persistent toxic substances (PTS) in China and possibly their regional transport in the Yellow and East China Seas region was studied. Organochlorines in atmospheric gas-phase and particulate matter were collected by high-volume sampling (filters and polyurethane foams) during 2 weeks in June 2003 (dry season) simultaneously at a Yellow Sea coastal site in an urban area, Qingdao, China, and a rural island site, Gosan, Jeju Island, Korea. Using GC methods, the samples were analysed for 9 persistent organic pollutants (POPs) regulated under the global POP convention, namely aldrin, chlordane ( cis- and trans-isomers CC and TC), DDT and metabolites ( o, p′-DDT, p, p′-DDD, and p, p′-DDE), dieldrin, endrin, heptachlor, hexachlorobenzene (HCB), mirex and PCB (congeners number 28, 52, 101, 153 and 180), and for hexachlorocyclohexane ( α-, β- and γ-isomers), a PTS and now considered for regulation under the convention, too. At the coastal site additionally o, p′-DDE and -DDD, β-endosulfan, isodrin, heptachlorepoxide and δ-HCH, and at the island site additionally p, p′-DDT and 12 additional PCB congeners were analysed. 9 samples were collected at the coastal and 15 (for PCBs 5) at the island site. Long-range advection pathways were determined based on analysed back-trajectory calculations. The mean concentrations of DDT and its metabolites, HCB, HCH, and PCB at the coast were in the 100–1000 pg m −3 range. Higher concentrations prevailed during nighttime. The levels were in general lower at the island site, but not for DDT. Local sources are likely. PCBs were even 2 orders of magnitude lower, suggesting that PCBs are not subject to regional transport but elevated concentrations in air are limited to the source areas. Organochlorine pesticide levels on the other hand were seemingly determined by regional transport over Mainland China rather than by emissions in the coastal area. The currently used pesticides mirex and chlordane were found at elevated levels, i.e. 79 (6.6–255) and 36 (<6–71) pg m −3, respectively, at the coast but not over the island. The POPs pesticides aldrin, dieldrin and endrin, never registered in China, were mostly found at <10 pg m −3 except for endrin at the coastal site (up to 400 pg m −3) and aldrin at the island site (up to 50 pg m −3).

Levels of Dichlorodiphenyltrichloroethane and Deltamethrin in Humans and Environmental Samples in Malarious Areas of Mexico

Mexico used dichlorodiphenyltrichloroethane (DDT) to control malaria until 1999, when it was replaced with deltamethrin for mosquito control. Thus, we performed environmental and exposure assessments to DDT and deltamethrin in the states of Chiapas and Oaxaca. In Chiapas, samples were obtained at the time when DDT was being used in the malaria control program, while in Oaxaca, samples were collected 2 years after the final spraying of DDT and 2 days after deltamethrin application. Mean concentrations of DDT and Dichlorodiphenyldichloroethylene (DDE), as measured in whole blood, were 67.8 and 86.7 μg/L for children living in Chiapas and 27.1 and 60.8 μg/L for adults, respectively. As expected, DDT levels were lower 2 years after the final application in Oaxaca (20.4 and 13.2 μg/L for children and adults, respectively). Sprayers in Chiapas had the highest levels of exposure, with 165.5 and 188.4 μg/L of DDT and DDE, respectively. Women living in Chiapas and Oaxaca also had significantly higher blood levels of DDT and DDE than those women living in areas where less DDT had been used. Deltamethrin exposure was assessed only in children living in Oaxaca; 50% of the exposed group had urinary levels of 3-phenoxybenzoic acid above the limit of detection (LOD) and 6% had levels above 25 μg/L (five times the LOD), with a negative trend with age (r=−0.33). In Chiapas we found higher DDT and DDE levels in soil than in Oaxaca. In the latter location, large amounts of DDT and DDE were found in sediment samples and deltamethrin was detected in indoor soil samples. Considering the environmental data, the blood level results can be explained by soil/dust ingestion, human milk ingestion, and consumption of fish and other contaminated foods.