Distribution of Organo-Chlorine Pesticides (DDT and HCH) Between Plant and Soil System

This paper reports a study of the distribution of organo-chlorine pesticides (DDT and HCH) between rice plants and the soil system by spraying before the heading stage at four different dosage levels – control, normal dosage (15 kg ha^–1 of 6% HCH and 7.5 kg ha^–1 of 25% DDT), double dosage and four times dosage. Soil and plant samples were taken respectively at the 1st h, 3rd, 10th, 20th, and 40th day after spraying and at the harvest time. The results indicate that less than 5% of HCH and 15% of DDT were absorbed by the surface of rice leaves for normal dosage. Most of both pesticides moved into the soil in solution after spraying. Compared with DDT, HCH was degraded and run off more easily. HCH residues in the surface soil layer (1–3 cm) were already below 6.4 g kg^–1 at the mature stage, lower than Chinese Environmental Quality Standard for Agricultural Soils: HCH <0.05 mg kg^–1. However DDT residues in the surface soil layer remained 172 g kg^–1, higher than the national standard: DDT <0.05 mg kg^–1. According to the test f OCP residues in rice seeds, it can be concluded that the OCP sprayed onto the surface of rice leaves can move into rice plants and accumulate in the seeds at the mature stage. HCH residues in rice seeds of the double and four times dosage treatments, and DDT residues in all treatments, exceeded the Chinese National Food Standard (HCH <0.10 mg kg^–1, DDT <0.20 mg kg^–1).     

Level of organochlorine pesticide residues in dry fruit nuts

The use of pesticides on cash crops and exportable food commodities had always been a serious concern. Fruits form one of the important constituents of human diet, in that they give one third of the requirement of calories, vitamins, and minerals. This study has been carried out to determine the level of organochlorine pesticides namely HCH, DDT and Endosulfan in raw fruit nuts. Nuts have proteins and high level of fat content. These properties of nuts attract organochlorine pesticides to accumulate. The analysis of organochlorine pesticide residues in commonly used dry fruits like Cashewnut, Walnut, Coconut, Chilgoza, Chironji, Makhana, Resins, Apricot, Almonds, Date palm, Pistachio nut collected from local market of Lucknow India has indicated presence of very low level of HCH (0.007-1.328 mg kg(-1)), DDT(ND-0.140 mg kg(-1)) and Endosulfan (ND-0.091 mg kg(-1)). There are no MRL values established for nuts in the country. This finding is based on a smaller number of samples, which however suggest that the presence of low level of DDT, HCH and Endosulfan might be due to environmental rather than direct exposure.     

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.     

珠江八大入海口表层沉积物中DDTs和HCHs残留调查

于2010年8月-2011年5月4次采集珠江八大人海口表层沉积物,采用气相色谱-电子捕获（GC—ECD）法分析沉积物中DDTs（p,P’-DDE、P,P’-DDD、0,P’-DDT、P,P-DDT）和HCHs（α-HCH、β-HCH、γ-HCH、δ-HCH）的污染现状。结果显示,珠江8大人海口表层沉积物中DDTs总含量介于1．02—3．08μg·kg-1之间（以干质量计,下同）,平均值为1．91μg·kg-1;HCHs总含量介于0．21—0．41μg·kg-1之间,平均值为0．31μg·kg-1。DDTs平均含量大于HCHs,其中P,P。DDT对污染的贡献最大,含量范围为ND～7．66μg·kg-1,平均值为2．12μg·kg-1。大部分样点伽（α-HCH）／w（γ-HCH）比值小于3,说明研究区α-HCH大都被降解,或者林丹正取代工业HCHs成为珠江口水环境中HCHs输入的主要来源;甜（DDT）／w（DDD＋DDE）比值大于2,表明沉积物中除早期农药残留外,仍然有新的DDTs类农药输入。     

Organochlorine pesticides in soils around Guanting Reservoir,China

Fifty-six representative samples of topsoil were collected around Guanting Reservoir, which is an important water source for Beijing. Concentrations of the insecticides HCH, DDT, and their metabolites were quantified by use of gas chromatography (GC) with electron capture detection (ECD). Organochlorine pesticides (OCPs) are still present in surface soils in the Guanting area. DDT accounts for about 93% of the total OCP content. Concentrations of α/γ, β/γ, and DDT/DDE are the result not only of historical use, but also of more recent depositions. Statistical analyses, including principal component analysis (PCA) and cluster analysis (CA), revealed associations between concentrations of OCPs and major soil characteristics. Geographical information system (GIS) technology was used to develop maps of the distributions of OCP concentrations. The areas of greatest contamination were primarily in the central part of the study area and were correlated with greater population density, heavier traffic, and more industrial activity.     

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.     

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.     

Role of phosphate solubilizing bacteria on rock phosphate solubility and growth of aerobic rice

Use of phosphate-solubilizing bacteria (PSB) as inoculants has concurrently increased phosphorous uptake in plants and improved yields in several crop species. The ability of PSB to improve growth of aerobic rice (Oryza sativa L.) through enhanced phosphorus (P) uptake from Christmas island rock phosphate (RP) was studied in glasshouse experiments. Two isolated PSB strains; Bacillus spp. PSB9 and PSB16, were evaluated with RP treatments at 0, 30 and 60 kg ha(-1). Surface sterilized seeds of aerobic rice were planted in plastic pots containing 3 kg soil and the effect of treatments incorporated at planting were observed over 60 days of growth. The isolated PSB strains (PSB9 and PSB16) solubilized significantly high amounts of P (20.05-24.08 mg kg(-1)) compared to non-inoculated (19-23.10 mg kg(-1)) treatments. Significantly higher P solubilization (24.08 mg kg(-1)) and plant P uptake (5.31 mg plant(-1)) was observed with the PSB16 strain at the highest P level of 60 kg ha(-1). The higher amounts of soluble P in the soil solution increased P uptake in plants and resulted in higher plant biomass (21.48 g plant(-1)). PSB strains also increased plant height (80 cm) and improved root morphology in aerobic rice. The results showed that inoculation of aerobic rice with PSB improved phosphate solubilizing activity of incorporated RP.     

Residues of 14C‐γ‐HCH in paddy after dusting,and the fate of γ‐HCH during refining process of rice bran oil

Paddy (rice) plants were dusted with 10% HCH containing ¹⁴C‐Γ‐HCH, at the rate of 2.5 kg a.i./ha and ¹⁴C‐residues were determined in different fractions of rice. Rice bran (0.187 ppm) had more of ¹⁴C‐residues than grain (0.026 ppm) and husk (0.042 ppm). The rice bran oil contained 0.129 ppm HCH residues. While degumming, dewaxing, alkali refining and bleaching had no effect, deodorisation alone eliminated 99.5% of added ¹⁴C‐residues in rice bran the oil during refining process.     

Effect of organic materials and rice cultivars on methane emission from rice field

A field experiment was conducted for two years on a sandy loam (Typic Ustochrept) soil of Punjab to study the effect of organic materials and rice cultivars on methane emission from rice fields. The methane flux varied between 0.04 and 0.93 mg m(-2) hr(-1) in bare soil and transplanting of rice crop doubled the methane flux (0.07 to 2.06 mg m(-2) hr(-1)). Among rice cultivars, significantly (p < 0.05) higher amount of methane was emitted from Pusa 44 compared to PR 118 and PR 111. Application of organic materials enhanced methane emission from rice fields and resulted in increased soil organic carbon content. The greatest seasonal methane flux was observed in wheat straw amended plots (229.6 kg ha(-1)) followed by farmyard manure (111.6 kg ha(-1)), green manure (85.4 kg ha(-1)) and the least from rice straw compost amended plots (36.9 kg ha(-1)) as compared to control (21.5 kg ha(-1)). The differential effect of organic materials in enhancing methane flux was related to total carbon or C:N ratio of the material. The results showed that incorporation of humified organic matter such as rice straw compost could minimize methane emission from rice fields with co-benefits of increased soil fertility and crop productivity.     

Chemical changes in agricultural soils of Korea: data review and suggested countermeasures

The monitoring of chemical properties, including heavy metals, in soils is necessary if better management and remediation practices are to be established for polluted soils. The National Institute of Agricultural Science and Technology initiated a monitoring study that investigated fertility and heavy metal contents of the benchmarked soils. The study covered paddy soils, upland soils, and horticultural soils in the plastic film houses, and orchard soils throughout the Korea from 1990 to 1998. Likewise, 4047 samples of paddy and 2534 samples of plastic house in 1999 and 2000 were analyzed through the Soil Environment Conservation Act. Soil chemical properties such as pH, organic matter, available phosphate and extractable calcium, magnesium and potassium contents, and heavy metal contents such as cadmium, copper, lead, zinc, arsenic, mercury, and cobalt contents were analyzed. The study showed that the average contents of organic matter, available phosphate, and extractable potassium rapidly increased in plastic house soils than in upland or paddy soils. Two kinds of fertilizer recommendation systems were established for the study: the standard levels by national soil average data for 77 crops and the recommendation by soil test for 70 crops. Standard nitrogen fertilizer application levels for cereal crops changed from 94 kg/ha in 1960s, 99 kg/ha in 1970s, 110 kg/ha in 1980s to 90 kg/ha in 1990s. The K2O-fertilizer also changed from 67 kg/ha in 1960s, 76 kg/ha in 1970s, 92 kg/ha in 1980s, and only 44 kg/ha in 1990s. In rice paddy fields, the average contents of Cd, Cu, Pb, and Zn in surface soils (0-15 cm depth) were 0.11 mg kg(-1) (ranged from 0 to 1.01), 4.70 mg kg(-1) (0-41.59), 4.84 mg kg(-1) (0-66.44), and 4.47 mg kg(-1) (0-96.70), respectively. In the uplands, the average contents of Cd, Cu, Pb, Zn, and As in surface soils (0-15 cm depth) were 0.135 mg kg(-1) (ranged from 0 to 0.660), 2.77 mg kg(-1) (0.07-78.24), 3.47 mg kg(-1) (0-43.00), 10.70 mg kg(-1) (0.30-65.10), and 0.57 mg kg(-1) (0.21-2.90), respectively. In plastic film houses, the average contents of Cd, Cu, Pb, Zn, and As in surface soil were 0.12 mg kg(-1) (ranging from 0 to 1.28), 4.82 mg kg(-1) (0-46.50), 2.68 mg kg(-1) (0-46.50), 31.19 mg kg(-1) (0.19-252.0), and 0.36 mg kg(-1) (0-4.98), respectively. In orchard fields, the average contents of Cd, Cu, Pb, Zn, As, and Hg in surface soils (0-20 cm depth) were 0.11 mg kg(-1) (ranged from 0-0.49), 3.62 mg kg(-1) (0.03-45.30), 2.30 mg kg(-1) (0-27.80), 16.60 mg kg(-1) (0.33-105.50), 0.44 mg kg(-1) (0-4.14), and 0.05 mg kg(-1) (0.01-0.54), respectively. For polluted soils with over the warning content levels of heavy metals, fine red earth application, land reconsolidation and soil amelioration such as lime, phosphate, organic manure, and submerging were recommended. For the countermeasure areas, cultivation of non-edible crops such as garden trees, flowers, and fiber crops; land reformation; and heavy application of fine red earth (up to 30 cm) were strongly recommended. Land use techniques should be changed to be harmonious with the environment to increase yield and income. Soil function characteristics should be taken into account.     

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.     

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.     

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.     

Pesticide Residues in Water From River Kaveri,South India

The residue levels of presistent chlorinated pesticides such as HCH (hexachlorocyclo-hexane) isomers and DDT (dichlorodiphenyl trichloroethane) compounds were quantified in water samples collected from the River Kaveri and its distributor River Coleroon in Tamil Nadu, South India. HCH showed higher levels in River Kaveri during premonsoon (July to September) and monsoon (October to December) months, reflecting the HCH usage during that season for paddy crops. But in the case of DDT no clear trend in residue level was observed. the α-HCH was detected as the dominant isomer in all the three sampling sites. Among DDT compounds, p,p'-DDT and p,p'-DDE showed higher percentage of the total. International comparison of residue levels revealed that the present values are comparable to the waters from Asian and South East Asian nations, but lower than some samples from other parts of India. the value of DDT is well below the EEC's maximum acceptable concentration for surface waters and lower than the recommended limit of 2000ng 1^-1 in USA water for protection of aquatic life (Water Quality Criteria, 1972).     

Accumulation of organochlorine insecticides in the blood of the general population of Nigeria

Gas Chromatographic determination of blood levels of organochlorine pesticides in people of Southern Nigeria is described. Among the compounds detected and quantified were the HCH‐isomers, DDT and its metabolites and dieldrin, the major pollutants being DDT, DDE and the HCH‐isomers. Delta‐HCH, HCB and Endrin were also detected in a few samples. Total DDT (DDT + DDE + DDD) ranged from 0.04–7.24 ppm, total HCH (alpha + beta + gamma) 0.08–5.64 ppm, and dieldrin 0.03–0.28 ppm.     

The concentration and distribution of organochlorine pesticides in the air from the karst cave, South China

Organochlorine pesticides (OCPs) in the air of Dayan Cave in Guilin were analyzed, to investigate the source and contamination levels. Generally, air outside of the cave had much higher concentrations than inside air, and both outside and inside air showed much lower contamination levels than those observed in other regions in China and abroad. The ratios of α-/γ-HCHs and the percentages of β-(or δ-)HCH implied a residue of historical local technical HCH contamination. The DDT concentrations, o,p'-DDT/p,p'-DDT, and p,p'-DDE/p,p'-DDT suggested fresh DDT-containing products acted as the primary source of DDT for the air in Dayan Cave. An intermediate level concentration of α-endosulfan (156.00?pg/m(3)) was observed in the outside air, implying local source was dominant. Based on the similar sources of HCH and DDT and the relationships between outside and inside air, it appeared that outside air pollutants affected on inside HCH and DDT's distribution. For other OCPs, outside air might be major contributor to inside air contamination under conditions of high concentrations in outside air compared with low levels in inside air for semi-closed karstic caves.     

Concentration of organochlorines in Ganges River dolphins from Patna,Bihar

Concentrations of DDT, HCH, aldrin and endosulfan were determined in river dolphins from the River Ganges, Patna. Among the organochlorines studied in the dolphins, DDT concentration was highest followed by HCH. This shows exposure of dolphins to these organochlorine pesticides. Presences of organochlorines to higher degree in tissues suggest that the river dolphins be at greater risk due to pesticidal contamination of the river system.     

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.     

Case study on nitrogen and phosphorus emissions from paddy field in Taihu region

The agricultural non-point source pollution by nitrogen (N) and phosphorus (P) loss from typical paddy soil (whitish soil, Bai Tu in Chinese) in the Taihu Lake region was investigated through a case study. Results shown that the net load of nutrients from white soil is 34.1 kg ha(-1) for total nitrogen (TN), distributed as 19.4 kg ha(-1), in the rice season and 14.7 kg ha(-1) in the wheat season, and for total phosphorus (TP) 1.75 kg ha(-1), distributed as 1.16 kg ha(-1) in the rice season and 0.58 kg ha(-1) in the wheat season. The major chemical species of N loss is different in the two seasons. NH4-N is main the form in the rice season (53% of TN). NO3-N is the main form in wheat season (46% of TN). Particle-P is the main form in both seasons, (about 56% of TP). The nutrient loss varied with time of the year. The main loss of nutrients happened in the 10 days after planting, 64% of TN and 42% of TP loss, respectively. Rainfall and fertilizer application are the key factors which influence nitrogen and phosphorus loss from arable land, especially rainfall events shortly after fertilizer application. So it is very important to improve the field management of the nutrients and water during the early days of planting.