Distribution,sources and potential risk of HCH and DDT in soils from a typical alluvial plain of the Yangtze River Delta region,China

Spatial distribution, sources and potential health risks of organochlorine pesticides (OCPs), including hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), in surface soils (n = 544) collected from a typical alluvial plain of the Yangtze River Delta region, China, were elucidated. Concentrations of ΣHCH and ΣDDT in soils ranged from less than the limit of detection (<LOD) to 99.0 ng g^?1, dry weight (dw) (mean 3.23 ng g^?1 dw) and <LOD to 600 ng g^?1 dw (mean 88.8 ng g^?1 dw), respectively. Historical applications of HCH and DDT were the major sources of the residue in soils. HCH was mainly distributed in Anthrosols in the southern part of the watershed, while DDT was mainly distributed in Cambosols in the northern part. The 95 % cumulative probability incremental lifetime cancer risks (ILCRs) of different age groups such as children, youths, and adults all exceeded the acceptable risk level of 10^?6 recommended by USEPA for carcinogenic chemicals. The spatial distributions of ∑ILCRs were consistent with concentrations of OCPs in soils, while they were slight different for the different age groups. Adult females had the greatest risk of OCPs in soils, followed by children, while youths had the least risk. The ingestion of OCPs in soils was the more important route of exposure compared with dermal and inhalation exposures. The concentration of OCPs in soils, the particulate emission factor, the fraction of dermal exposure ratio, and the soil ingestion rate were the major contributing variables to total ILCRs according to sensitivity analyses.     

Polychlorinated biphenyls and organochlorine pesticides in amniotic fluids of pregnant women in south-central Turkey†

The concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in amniotic fluid of 200 pregnant women from the Cukurova region of Turkey. The concentrations of OCPs [hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), dichlorodiphenyl trichloroethane (p,p′-DDT), and various metabolites], and different PCB congeners (28, 52, 101, 118, 138, 153, 180) were determined by gas chromatography with electron capture detection as follows: HCB 6.6 ± 4.7, ΣHCH 21.6 ± 14.2, ΣDDT 12.5 ± 7.5, and ΣPCBs 74.0 ± 54 ng mL^?1. Correlations of maternal or gestational age and levels of OCPs and PCBs were not significant. The levels of these organochlorine compounds (OCs) were below detection limit for 5% of the samples, 80% contained more than one OC. This study illustrates that prenatal exposure of a fetus to OCs is prevalent in the Cukurova region.     

Organochlorine pesticides (HCHs and DDTs) in soils along the north coastal areas of the Bohai Sea,China

A systematic survey of organochlorine pesticides (OCPs) including hexachlorocyclohexane isomers (α-HCH, β-HCH, γ-HCH, δ-HCH and ΣHCH) and dichlorodiphenyltrichloroethane metabolites (p,p′-DDT, p,p′-DDE, o,p′-DDT, p,p′-DDD and ∑DDT) in soils along the north coastal areas of the Bohai Sea, China, has been lacking. In this study, 31 representative surface soil samples were collected along the north coastal and riverine areas of the Bohai Sea to characterise the potential for adverse effects of ∑HCH, ∑DDT and their individual isomers and transformation products. Concentrations of ΣHCH and ΣDDT in soils ranged from less than the limit of detection (1 ng · g^?1 dw (mean: 3.5 ng · g^?1 dw) and2 ng · g^?1 dw (mean: 1.7 × 10¹ ng · g^?1 dw), respectively. Compared with studies of OCPs in soils from other locations, concentrations of HCHs and DDTs observed in this study were moderate. Concentrations of OCPs observed in soils were generally less than proposed reference values. HCH residues were a mixture of historical technical HCH and current lindane sources. The pattern of DDTs was consistent with historical releases of technical DDTs. Selected soil physicochemical properties did not explain the sorption and/or partitioning of HCHs or DDTs.     

Ecotoxicological assessment of sediment from Texcalac River and agricultural soil of riverside area,in Tlaxcala,Mexico

This study assesses the potential risk of Texcalac River and riparian area. The p,p′ DDT and ∑DDTs levels in agricultural soils (3.9–208.0?µg/kg) and in surface sediments (0.6–137?µg/kg) surpassing the guidelines for protection of aquatic life (75% > TEC). The ∑PCBs concentration oscillated from 135 to 93941?µg/kg; the half of sediments exceeded the international guidelines (PEL, PEC), as well as two soils (SQGE?=?500?µg/kg). The TEQ concentration of four PCB-DL varied between 0.1 and 24.9?µg TEQ/kg, chiefly affected by PCB 169. Five sediments were lethal for E. foetida, two resulted to be cytotoxic and the 58% produced genotoxicity higher than negative control (A?=?0.28?±?0.05; DICA?=?72.5?±?16.9 au). Likewise, 31.6% of samples increased the micronuclei frequency in V. faba in comparison with negative control. The analytical data and the bioassays results suggest a significant and immediate risk to exposed biota of this region, highlighting a specific area in Texcalac River and other one in Sambrano Ravine. It is necessity assess the dispersion of pollutants and perform biomonitoring studies that display the exposure levels in biota with the goal to characterise the ecotoxicological risk.     

Organochlorine pesticide residues in fodder from rural areas of Haryana,India

Residues of organochlorine pesticides (OCPs) namely 1,2,3,4,5,6-hexachlorocyclohexane isomers (HCH-isomers), 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (DDT) and its metabolites, and endosulfan stereoisomers were analyzed in dry and green fodder samples from rural areas of Ambala, Gurgaon, and Hisar districts of Haryana, India during winter, summer, and post-monsoon seasons. The HCH isomers γ-HCH and β-HCH, and DDT and its metabolites p,p′-DDD, p,p′-DDE, and p,p′-DDT had more traceability in test samples as compared to other isomers and metabolites studied. Total OCPs (ΣOCPs), i.e., ΣHCH, ΣDDT, and Σendosulfan were found to be the highest in wheat straw (1.1–1.2?mg?kg^?1) from Ambala and Gurgaon, followed by that in sorghum straw (0.46?mg?kg^?1) from Hisar. Dry fodder samples were found to have relatively higher residue levels than green fodders. In case of green fodder samples, maximum ΣOCP residues of 0.44?mg?kg^?1 were found in whole plant samples of sorghum from Gurgaon district followed by that in pearl millet (0.40?mg?kg^?1) from Ambala. The findings indicate highly significant differences (p?>?0.0001) in ΣOCPs and ΣDDT in wheat straw between different districts and reveal the persistence of OCP residues in both dry and green fodder samples in the study area.     

Concentrations of Hchs and Ddts in the Tissues of River Dolphins,Platanista Gangetica,From the River Ganges,India

Abstract

Concentrations of HCH and DDT organochlorine insecticide residues were measured in blubber, muscle and oil samples from three specimens of river dolphins, Platanista gangetica, from the River Ganges, India. Concentrations of HCH and DDT ranged from 94 to 289 ng g^?1 and from 1324 to 9388 ng g^?1 on wet wt. basis respectively. Comparisons are made with other aquatic mammals and other studies on river dolphins. P. gangetica appears to exhibit similar patterns of accumulation with age and with ß-HCH and p-p′-DDE being accumulated to higher levels than other HCH isomers and parent DDT and its other metabolites, respectively. These organochlorines may pose a health risk to river dolphin populations that are already showing evidence of environmental stress. Further studies are recommended.     

Comprehensive characterization of PAHs profile in Serbian soils for conventional and organic production: potential sources and risk assessment

This study presents a comprehensive characterization of occurrence and levels of 16 polycyclic aromatic hydrocarbons (PAHs) in arable soils used for conventional and organic production in northern and central part of Serbia as well as cross-border region with Hungary. Furthermore, this study includes a characterization of PAH sources and carcinogenic/non-carcinogenic human health risk for PAHs accumulated in analysed arable soils. The total concentration of 16 PAHs varied between 55 and 4584 µg kg^?1 in agricultural soil used for conventional production and between 90 and 523 µg kg^?1 in agricultural soil used for organic production. High molecular weight (HMW) PAHs were dominant compounds with similar contribution in both soil types (86% and 80% in conventional and in organic soil, respectively). Principal component analysis and diagnostic ratios of selected PAHs were used for identification of PAH sources in the analysed soils. Additionally, positive matrix factorization was applied for quantitative assessment. The results indicated that the major sources of PAHs were vehicle emissions, biomass and wood combustion, accounting for?~?93% of PAHs. Exposure of farmers assessed through carcinogenic (TCR) and non-carcinogenic (THQ) risk did not exceed the acceptable threshold (TCR?<?10^–6 and THQ?<?1). Oral ingestion was the main exposure route which accounted for 57% of TCR and 80% of THQ. It was followed by dermal contact. This investigation gives a valuable data insight into the PAHs presence in arable soils and reveals the absence of environmental and health risk. It also acknowledges the importance of comprehensive monitoring of these persistent pollutants.

     

Spatial variability and temporal trends of HCH and DDT in soils around Beijing Guanting Reservoir,China

Spatial variability and temporal trends in concentrations of the organochlorine pesticides (OCPs), hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), in surface soils around Beijing Guanting Reservoir (GTR) were studied in 2003 and 2007. Concentrations of the two OCPs in soils around GTR were generally less than reference values set by the Chinese government for the protection of agricultural production and human health. Among the OCPs, β-HCH and p, p′-DDE were the two predominant compounds. This result indicates that the HCH and DDT residues in soils were primarily from historical use. Based on kriging, a spatial distribution of HCH and DDT around the GTR was observed. Spatial variability indicated how HCH and DDT had been applied and been distributed in the past. Between 2003 and 2007, concentrations of HCH and DDT decreased more rapidly in orchard soils than those in fallow soils.     

Organochlorine pesticides and PCBs in sediments from the Yangtse River,China

Organochlorine Pesticides and PCBs pollution levels were determined in sediment samples taken from three sites along the Yangtse River (Nanjing part). The concentrations of various pesticides were in the range of 1.42–8.06 ng/g (t‐HCH), and <0.01–4.12ng/g (t‐DDT), while the concentrations of PCBs were below detection limit at all three sites. The contamination by Organochlorine Pesticides and PCBs in sediments from the Yangtse River was not significant when compared with that reported in the literature from some other countries’ rivers, which may be due to the high flow velocity and water amount of the Yangtse River.     

Factors affecting HCH and DDT in soils around watersheds of Beijing reservoirs,China

The factors that influence the dynamics of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) in soils around the watersheds of Beijing reservoirs were examined. Compared with other studies on HCH and DDT in soils and established reference values, the concentrations of HCH and DDT in soils around our study area were relatively low. The relationships between HCH and DDT concentrations and land use, soil texture, and soil properties were discussed. HCH and DDT concentrations were higher in arable soils than those in uncultivated fallow soils. Although land use was the most important factor affecting HCH and DDT residues, additional factors such as soil texture and soil total organic carbon were also involved in pesticide retention in soils. The results indicated that the historical agricultural applications of HCH and DDT were the major source of their residues. Atmospheric deposition, as well as long-distance transportation and inputs from surrounding weathered agricultural soils may also serve as important sources of HCH and DDT residues in the watersheds.     

The potential ecological risk of soil trace metals following over five decades of agronomical practices in a semi-arid environment

The concentration and potential ecological risk of Mn, Zn, Cu, and Cd in the surface soils (0–30?cm) belonging to 12 soil profiles and 4 soil types (Vertisols, Chernozems, Calcisols, and Cambisols) from the cultivated soils and the corresponding uncultivated soils were investigated. Long-term cultivation caused a considerable build-up diethylene-triamine pentaacetic acid (DTPA)-extractable Mn (7–55%), and Cd (12–31%) as well as the total form of Zn (3–14%), Cu (8–25%), and Cd (33–78%) in all soil types. Following long-time cropping, total Zn (mean?=?73?mg?kg^?1), Cu (mean?=?33?mg?kg^?1), and Cd (mean?=?3.14?mg?kg^?1) and DTPA Zn (mean?=?1.2?mg?kg^?1) and Cu (mean?=?2.44?mg?kg^?1) were below their maximum allowable limits. However, the average amount of DTPA Cd in the tilled soils (min?=?0.4, max?=?0.75, mean?=?0.55?mg?kg^?1) was above its maximum permissible limit mainly due to the over application of phosphate fertilisers and the pesticides. Considering the potential ecological risk (RI) assessment of the cultivated soils (min?=?44, max?=?70, mean?=?54), the soil types were categorised as low (RI?≤?50) to moderate (50?相似文献   

Concentrations of polycyclic aromatic hydrocarbons in soils of a mangrove forest affected by forest fire

Surface soils affected by forest fires from Igbanko mangrove forest in Nigeria were analyzed for 16 EPA priority polycyclic aromatic hydrocarbons (PAHs) using gas chromatography–mass spectrometry (GC–MS). The total PAHs concentrations in the soils ranged from 63 to 188?µg?kg^?1 dry weight (average: 108?µg?kg^?1). The three predominant PAHs in the soils were naphthalene (Na), fluoranthene (Flu), and benzo(b)fluoranthene (BbF). Compared to the control sample (19?µg?kg^?1), elevated PAHs concentrations were observed in the soils, an indication of some level of PAHs contamination. PAHs source diagnostic ratios of Flu/(Flu?+?Pyr) and Ant/(Ant?+?Phe) indicated that the PAHs have a pyrogenic origin which may have resulted from combustion of grass, wood, or coal. An assessment based on Canadian soil quality guidelines indicated that the studied locations do not pose any serious adverse risk on human health.     

Organochlorine pesticides in surface soils and sediments from obsolete pesticides dumping site near Lahore city,Pakistan: contamination status and their distribution

Surface soil and sediment samples were collected from the surroundings of Lila stream, which passes through the obsolete pesticides dumping area Kalashah Kaku near Lahore city, to evaluate the residual levels of 19 organochlorine pesticides (OCPs), their distribution and potential sources. OCPs followed the order: ∑ DDT>∑ HCH>dicofol>endrin>heptachlor>dieldrin. Ratios of β to γ-HCH highlighted an old source of technical HCH in the study area, whereas the predominance of p, p′-DDT and p, p′-DDE indicated presence of technical DDT in surface soils. Factor analysis based on principal component analysis identified the origin of OCPs from industrial activities in Kalashah Kaku and waste dumping from Ittehad Chemical Industries via open drains into Lila stream. Greater levels of DDTs and HCHs above quality guideline pose potential exposure risk to biological organisms, safety of agricultural products and human health in the surrounding of Lila stream.     

Organochlorine residues in maternal milk from inhabitants of the Thohoyandou area,South Africa

The presence of organochlorine compounds (OC) such as DDT and their metabolites in the environment have created a significant environmental concern over the years due to adverse effects. Consequently, DDT has been banned in many countries. However, it is still used in some countries including South Africa, particularly for vector-borne disease eradication programmes. Since the presence of DDT and its metabolites may provide an indication of the general exposure and use of these compounds, there was a need for such a study. Human breast milk samples (n = 30) were collected from mothers within the age range of 19–40 years from the Thohoyandou area, South Africa. The liquid–liquid extraction method was used to extract DDT and its metabolites from the samples. The crude extracts were subjected to column chromatography for measurements of OC levels. The concentration ranges of the contaminants were as follows: not detected (ND) to1770 ng g^?1 (2,4′-DDE); ND to 3977 ng g^?1 (4,4′-DDE); ND to 3250 ng g^?1 (2,4′-DDD); ND to 2580 ng g^?1 (4,4′-DDD) and ND to 2847 ng g^?1 (4,4′-DDT). The mean ΣDDE, ΣDDD and ΣDDT obtained from the villages were 1180 ng g^?1, 830 ng g^?1 and 690 ng g^?1, respectively. The total DDT ranged from 820–7473 ng g^?1. The estimated daily intake varied from 260 to 4696 ng g^?1, ND-10551 ng g^?1 and ND-4237 ng g^?1 for DDE, DDD and DDT, respectively. These values are significantly higher than the FAO/WHO acceptable daily intake (ADI) of 20 ng g^?1. The ΣDDT was found to decrease with increasing age of the mothers. The observed high levels of DDE compared to DDT indicated chronic exposure of the mothers to DDT, which is metabolized to DDE and retained in the body.     

Levels and distributions of organochlorine pesticides in the soil–groundwater system of vegetable planting area in Tianjin City,Northern China

To study the influence of long-term pesticide application on the distribution of organochlorine pesticides (OCPs) in the soil–groundwater system, 19 soil samples and 19 groundwater samples were collected from agricultural area with long-term pesticide application history in Northern China. Results showed that the composition of OCPs changed significantly from soil to groundwater. For example, ∑DDT, ∑HCH, and ∑heptachlor had high levels in the soil and low levels in the groundwater; in contrast, endrin had low level in the soil and high level in the groundwater. Further study showed that OCP distribution in the soil was significantly influenced by its residue time, soil organic carbon level, and small soil particle contents (i.d. <0.0002 mm). Correlation analysis also indicates that the distribution of OCPs in the groundwater was closely related to the levels of OCPs in the soil layer, which may act as a pollution source.     

Health risk assessment of groundwater arsenic pollution in southern Taiwan

Residents of the Pingtung Plain, Taiwan, use groundwater for drinking. However, monitoring results showed that a considerable portion of groundwater has an As concentration higher than the safe drinking water regulation of 10 μg/L. Considering residents of the Pingtung Plain continue to use groundwater for drinking, this study attempted to evaluate the exposure and health risk from drinking groundwater. The health risk from drinking groundwater was evaluated based on the hazard quotient (HQ) and target risk (TR) established by the US Environmental Protection Agency. The results showed that the 95th percentile of HQ exceeded 1 and TR was above the safe value of threshold value of 10^?6. To illustrate significant variability of the drinking water consumption rate and body weight of each individual, health risk assessments were also performed using a spectrum of daily water intake rate and body weight to reasonably and conservatively assess the exposure and health risk for the specific subgroups of population of the Pingtung Plain. The assessment results showed that 0.01–7.50 % of the population’s HQ levels are higher than 1 and as much as 77.7–93.3 % of the population being in high cancer risk category and having a TR value >10^?6. The TR estimation results implied that groundwater use for drinking purpose places people at risk of As exposure. The government must make great efforts to provide safe drinking water for residents of the Pingtung Plain.     

Human risk assessment of As,Cd, Cu and Zn in the abandoned metal mine site

The cancer risk and the non-cancer hazard index for inhabitants exposed to As, Cd, Cu and Zn in the soils and stream waters of the abandoned Songcheon Au–Ag mine area were evaluated. Mean concentrations of As, Cd, Cu, Pb and Zn in agricultural soils were 230, 2.5, 120, 160, and 164 mg kg⁻¹, respectively. Mean concentrations of As, Cd and Zn of the water in the stream where drinking water was drawn was 246 μg L⁻¹, 161 μg L⁻¹ and 3899 μg L⁻¹, respectively. These levels are significantly higher than the permissible levels for drinking water quality recommended by Korea and WHO. The resulting human health risks to farmers who inhabited the surrounding areas due to drinking water were summarized as follows: (1) the non-cancer health hazard indices showed that the toxic risk due to As and Cd in drinking water were 10 and 4 times, respectively, greater than those induced by the safe average daily dosages of the respective chemicals. (2) the cancer risk of As for exposed individuals through the drinking water pathway was 5 in 1000, exceeded the acceptable risk of 1 in 10,000 set for regulatory purposes.     

Geochemistry and health risk assessment of arsenic exposure to street dust in the zinc smelting district, Northeast China

The aim of this study was to investigate arsenic (As) accumulation in street dust and health risk of population. The investigation concentrated on: a. pollution levels of As in street dust; b. spatial distribution of As in street dust; c. physicochemical properties analysis of street dust; and d. assessment of population health risk due to As exposure to street dust. As concentration in street dust ranged from 3.33 to 185.1?mg?kg^?1, with a mean of 33.10?mg?kg^?1, which was higher than the background value of Liaoning soil. As contamination level of the area closing to Huludao Zinc Plant (HZP) was highest. Spatial variation showed that the pollution center was close to HZP, formed radial distribution pattern and extended to the northeast and southwest of HZP. The pH and organic matter of street dust were both higher than the background values of soil in Liaoning. There was significantly negative correlation between As concentration and the pH. The mass percentages of particles 180?C100,?<100?C75,?<75?C63, and?<63???m were 29.8, 3.7, 21.3, and 4.2?%, respectively. The highest of As concentration was found in the smallest particle size (<63???m). As loadings in the particles of grain size 180?C100 and?<75?C63???m were higher than other particle fractions. Results of the risk assessment indicated that the highest risk was associated with the ingestion of street dust particles. Health risk for different use scenarios to human decreased in the order of HZP?>?Industrial district?>?School?>?Commercial center?>?Residential area. Around HZP, Hazard Index (HI) for children and cancer risk of As by street dust exposure exceeded the acceptable values. It indicated that there was a potential adverse effect on children health by As exposure to the street dust of Huludao.     

Occurrence and distribution of organochlorine residues and metals in sediment,water and fish in the catchment area of lake baiyangdian,china

The occurrence and distribution of metals (Al, Cd, Cr, Cu, Pb, Zn), organochlorine residues (HCH, DDT and metabolites, PCBs) and EOC1 (extractable organic bound chlorine) were monitored in 1993 and 1996 in sediment, water and fish in the catchment area of Lake Baiyangdian, China. The levels of the metals, especially Cd and Zn, were significantly higher in the sediment than those in non‐polluted areas. PCBs and chlorinated pesticides constituted only a minor part (< 8.4%) of the extractable organic bound chlorine, indicating the presence of additional, unknown, organochlorine residues. Among the pesticides, DDT was widely distributed and high levels occurred in fish despite a ban of its production and use in 1983. The low quotient of pp‐DDT/pp‐DDE in sediment and fish indicated that the input of DDT to the catchment area was not of recent origin.     

Organochlorine pesticide and polychlorinated biphenyl residues in human milk from Tabriz,Iran

Human breast milk samples, collected during April 2007 in Tabriz, Iran, were analyzed for organochlorine (OC) pesticides, such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), α, β, and γ-hexachlorocycloexane (HCH) isomers and six polychlorinated biphenyls (PCB) congeners (IUPAC Nos. 28, 52, 101, 138, 153, and 180). Organochlorine pesticides and OCB were both prevalent in the samples of human breast milk. Average concentrations of HCB, DDT, HCH, and PCB were 1020, 1930, 1660, and 690 ng g^?1 lipid weight, respectively. A positive correlation was observed between concentration of OC in human breast milk and mothers age with primiparae. Women having higher OC concentrations than multiparae women suggests that these parameters influence the OC burden in lactating women. The estimated tolerable daily intakes (TDIs) of HCH, HCB and PCB solely from human breast milk were 100, 46, and 43% of samples, respectively, exceeding guideline thresholds given as TDI proposed by Health Canada. Although high daily intakes may raise concerns for possible adverse effects of OC, women in Tabriz are recommended to breastfeed due to the numerous advantages for mother and child.