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PubMed2006

Determination of DNA damage in floriculturists exposed to mixtures of pesticides.

The aim of the study was to determine possible DNA damage in floriculturists chronically exposed to pesticides. Leukocytes from 52 workers, 46 environmentally exposed, and 38 control individuals were evaluated with the comet assay. Serum from all individuals was also analyzed for pesticides using gas chromatography coupled to mass spectrometry. A statistically significant difference in DNA fragmentation in the pesticide exposed group compared to the other two groups (P < .001) was found. No differences between environmentally exposed and control individuals were detected. The statistical analysis showed no significant correlation between DNA damage and sex, age, drinking or smoking habits, as well as years of exposure. One or more pesticides were detected in 50% of the floriculturists, while in the rest of the individuals, a chemical related with the preparation of pesticides, such as additives, plasticizers, or solvents, was found. Our study shows that chronic exposure to pesticides produces DNA damage in floriculturists. It also suggests that this type of monitoring could be valuable in recommending preventive measures.

Journal Article↗
PubMedDate not supplied

Organophosphate pesticide exposures of traditional and integrated pest management farmers from working air conditions: a case study in Thailand.

Concentrations of organophosphate pesticides, including chlorpyrifos and methyl parathion, were measured in ambient air breathed by farmers in Tambon Bang Rieng, Thailand. An exposure assessment and comparison was made between the levels of pesticide exposure of traditional and integrated pest management (IPM) farmers. Thirty-three air samples were collected during pesticide spraying. Traditional farmers were exposed to higher levels of the pesticide(s), with an average concentration of 0.19 mg/m3, compared with 0.037 mg/m3 for the IPM farmers. It was estimated that a farmer of Tambon Bang Rieng would be exposed to 81-12,261 mg of the organophosphate pesticide(s) via inhalation throughout his or her lifetime. Moreover, traditional farmers absorbed more of pesticide via inhalation than did IPM farmers.

Agriculture↗
PubMedDate not supplied

Use of pesticides and its impact on health of farmers in South India.

The relationship between extent of pesticide use and signs and symptoms of illnesses due to exposure was assessed in a cross-sectional survey of 631 farmers (537 men and 94 women) in South India. Responses to questionnaires showed that 433 farmers (68.6%) sprayed pesticides themselves and were thus directly exposed. More than 75% used moderately or highly hazardous pesticides; 88% used no protection while handling pesticides. About 50% of sprayers mixed different brands. Retailers were the source of information about pesticides for 56%. The farmers reported excessive sweating (36.5%), burning/stinging/itching of eyes (35.7%), dry/sore throat (25.5%), and excessive salivation (14.1%), all more prevalent among sprayers. Among men, excessive sweating and eye and throat problems were significantly associated with exposure. There is a need to raise farmers' and authorities' awareness of the need to use protective gear when handling pesticides.

Adult↗
PubMedDate not supplied

Semen quality and reproductive sex hormone levels in Peruvian pesticide sprayers.

To determine the association between occupational pesticide exposure and semen quality among sprayers using organophosphate (OPs) pesticides, 31 pesticide sprayers and 80 men who were not exposed were studied. Semen and blood samples were obtained one day after last pesticide application. Semen samples were analyzed for sperm concentration, percentage of sperm motility, percentage of normal morphology, and fructose and zinc concentrations. Blood samples were analyzed for sex hormones. Pesticide sprayers had significantly reduced age-adjusted seminal volume, percentage of motility, percentage of sperm with normal morphology, serum luteinizing hormone, serum testosterone levels, and seminal zinc concentration (a marker of prostate function), as well as significantly increased time of liquefaction, seminal pH, percentage of immature sperm morphology, and leukocyte concentration. These findings provide further evidence that occupational exposures to OP pesticides adversely affect semen quality and sex hormones.

Agriculture↗
PubMed2003

Prevalence of pesticide exposure in young males (</= 50 years) with adenocarcinoma of the prostate.

Evidence implicating pesticides as causative agents of prostate cancer is controversial, and specifically, data in young adults is lacking. Hence, we performed a preliminary study evaluating the relationship between pesticide exposure and prostate cancer in young males. After approval from the University of North Dakota Institutional Review Board and Human Subjects Committee, a retrospective study was performed on all young males (</ = 50 years) with a biopsy-proven diagnosis of carcinoma of the prostate. The records of all patients aged less than/equal to 50 years, with a diagnosis of adenocarcinoma of the prostate, from January 1991 through December 2001 were reviewed. Pesticide risk assessment interviews were performed by a single member of the team, for consistency, via telephone on the basis of a pre-determined questionnaire investigating occupations and hobbies with special emphasis on: Duration of exposure. An exposure index was calculated for each interviewed subject according to the following formula: hours/day x days/year x years. Patients with an exposure index >2400 hours were considered as 'exposed.' The 2400 hour cut-off value was chosen on the basis of previous reports indicating that this figure represents heavy exposure to genotoxic agents. Statistical analysis was obtained using SPSS-10ledR;. Between 1991 and 2001, 61 young males with adenocarcinoma of the prostate were identified, of whom 56 patients with a mean age of 47 years (range: 40-49) had complete records of treatment and could be contacted for completion of the questionnaire. The most common stage at presentation was Stage III and the mean Gleason's score was 7.5 (range 5-9). Interestingly, almost a third (16/56, 28.6%) of patients had stage IV disease at presentation. 37/56 (66.1%) patients had 'significant' exposure in our study. In addition, interestingly, the mean survival in the subgroup of patients with pesticide exposure was 11.3 months (SD: +/- 2.3 months), while the mean survival in the patients without pesticide exposure (n = 19) was 20.1 months (SD: +/- 3.1 months), with p-value <0.01. Although our study is relatively small, it does reveal preliminary evidence linking pesticide exposure to the early development of, possibly aggressive, prostate adenocarcinoma. Future, larger, epidemiological studies are needed to confirm the findings of our study.

Journal Article↗
PubMed2006

Dialkyl phosphate metabolites of organophosphorus in applicators of agricultural pesticides in Majes - Arequipa (Peru).

BACKGROUND: Organophosphorus (OPs) pesticides are the most commonly used pesticides in Peruvian agriculture. The population at risk for OPs exposure includes formulators, applicators and farmers. Majes Valley is the most important agricultural center of the Southern region of Peru. The present study was aimed to determine the knowledge about using OPs, safety practice and urinary dialkylphosphate metabolites on OP applicators in the Majes Valley, Peru. METHODS: This study was based on a questionnaire which included socio-demographic characteristics, knowledge of safety practices to handling OPs, characteristics of pesticide application and use of protective measures to avoid pesticide contamination. Exposure was assessed by measuring six urinary OP metabolites (DMP, DMTP, DMDTP, DEP, DETP, and DEDTP) by gas chromatography using a single flame photometric detector. The sample consisted of 31 men and 2 women aged 20 - 65 years old. RESULTS: 76% of applicators had at least one urinary dialkylphosphate metabolite above the limit of detection. The geometric mean (GM) and the geometric standard deviation (GSD) of DMP and DEP were 5.73 microg/g cr. (GSD 2.51), and 6.08 microg/g cr. (GSD 3.63), respectively. The percentage of applicators with detectable DMP, DMDTP, and DMTP in urine was 72.72%, 3.03%, and 15.15%, respectively, while the corresponding figures for DEP, DETP, and DEDTP were 48.48%, 36.36% and 15.15%, respectively. There was no significant association between the use of protection practices and the absence of urine OPs metabolites suggesting inadequate protection practices. CONCLUSION: The pesticide applicators in Majes Valley have significant exposure to OP pesticides, probably due to inappropriate protective practices. Future work should evaluate possible health effects.

Journal Article↗
PubMed2003

Species variation in pesticide-induced blood-brain barrier dysfunction.

Neurological disorders following acute or chronic exposure to pesticides have been reported in a number of human cases. However, the mechanism(s) by which pesticides produce central nervous system dysfunction is not clear. The objective of the present study was to examine the functional status of blood-brain barrier (BBB) in rats and mice exposed to selected pesticides of different chemical groups. Adult male albino rats and mice were exposed (1/10 of LD50) daily to dichlorvos (organophosphate), lindane (organochlorine) and carbofuran (carbamate) through oral intubation for 3 days. The status of BBB was evaluated by determining brain sodium fluorescein dye uptake and brain uptake index (BUI) in relation to serum dye level. The brain dye uptake and BUI in pesticide-exposed rats did not differ significantly in comparison to that of controls. However, brain dye uptake and BUI were increased significantly in mice exposed to dichlorvos (85%, 40%), lindane (79%, 26%) and carbofuran (129%, 61%). The results of this study show that mouse BBB system is more sensitive to pesticide-induced breach as compared to that of rat. These variations may have a role in determining the outcome of pesticide neurotoxicity in different species.

Administration, Oral↗
PubMed2003

Organophosphorus pesticide exposure of urban and suburban preschool children with organic and conventional diets.

We assessed organophosphorus (OP) pesticide exposure from diet by biological monitoring among Seattle, Washington, preschool children. Parents kept food diaries for 3 days before urine collection, and they distinguished organic and conventional foods based on label information. Children were then classified as having consumed either organic or conventional diets based on analysis of the diary data. Residential pesticide use was also recorded for each home. We collected 24-hr urine samples from 18 children with organic diets and 21 children with conventional diets and analyzed them for five OP pesticide metabolites. We found significantly higher median concentrations of total dimethyl alkylphosphate metabolites than total diethyl alkylphosphate metabolites (0.06 and 0.02 micro mol/L, respectively; p = 0.0001). The median total dimethyl metabolite concentration was approximately six times higher for children with conventional diets than for children with organic diets (0.17 and 0.03 micro mol/L; p = 0.0003); mean concentrations differed by a factor of nine (0.34 and 0.04 micro mol/L). We calculated dose estimates from urinary dimethyl metabolites and from agricultural pesticide use data, assuming that all exposure came from a single pesticide. The dose estimates suggest that consumption of organic fruits, vegetables, and juice can reduce children's exposure levels from above to below the U.S. Environmental Protection Agency's current guidelines, thereby shifting exposures from a range of uncertain risk to a range of negligible risk. Consumption of organic produce appears to provide a relatively simple way for parents to reduce their children's exposure to OP pesticides.

Agriculture↗
PubMed2004

In utero pesticide exposure, maternal paraoxonase activity, and head circumference.

Although the use of pesticides in inner-city homes of the United States is of considerable magnitude, little is known about the potentially adverse health effects of such exposure. Recent animal data suggest that exposure to pesticides during pregnancy and early life may impair growth and neurodevelopment in the offspring. To investigate the relationship among prenatal pesticide exposure, paraoxonase (PON1) polymorphisms and enzyme activity, and infant growth and neurodevelopment, we are conducting a prospective, multiethnic cohort study of mothers and infants delivered at Mount Sinai Hospital in New York City. In this report we evaluate the effects of pesticide exposure on birth weight, length, head circumference, and gestational age among 404 births between May 1998 and May 2002. Pesticide exposure was assessed by a prenatal questionnaire administered to the mothers during the early third trimester as well as by analysis of maternal urinary pentachlorophenol levels and maternal metabolites of chlorpyrifos and pyrethroids. Neither the questionnaire data nor the pesticide metabolite levels were associated with any of the fetal growth indices or gestational age. However, when the level of maternal PON1 activity was taken into account, maternal levels of chlorpyrifos above the limit of detection coupled with low maternal PON1 activity were associated with a significant but small reduction in head circumference. In addition, maternal PON1 levels alone, but not PON1 genetic polymorphisms, were associated with reduced head size. Because small head size has been found to be predictive of subsequent cognitive ability, these data suggest that chlorpyrifos may have a detrimental effect on fetal neurodevelopment among mothers who exhibit low PON1 activity.

Adult↗
PubMed2004

Low-dose agrochemicals and lawn-care pesticides induce developmental toxicity in murine preimplantation embryos.

Occupational exposures to pesticides may increase parental risk of infertility and adverse pregnancy outcomes such as spontaneous abortion, preterm delivery, and congenital anomalies. Less is known about residential use of pesticides and the risks they pose to reproduction and development. In the present study we evaluate environmentally relevant, low-dose exposures to agrochemicals and lawn-care pesticides for their direct effects on mouse preimplantation embryo development, a period corresponding to the first 5-7 days after human conception. Agents tested were those commonly used in the upper midwestern United States, including six herbicides [atrazine, dicamba, metolachlor, 2,4-dichlorophenoxyacetic acid (2,4-D)], pendimethalin, and mecoprop), three insecticides (chlorpyrifos, terbufos, and permethrin), two fungicides (chlorothalonil and mancozeb), a desiccant (diquat), and a fertilizer (ammonium nitrate). Groups of 20-25 embryos were incubated 96 hr in vitro with either individual chemicals or mixtures of chemicals simulating exposures encountered by handling pesticides, inhaling drift, or ingesting contaminated groundwater. Incubating embryos with individual pesticides increased the percentage of apoptosis (cell death) for 11 of 13 chemicals (p <or= 0.05) and reduced development to blastocyst and mean cell number per embryo for 3 of 13 agents (p <or= 0.05). Mixtures simulating preemergent herbicides, postemergent herbicides, and fungicides increased the percentage of apoptosis in exposed embryos (p <or= 0.05). Mixtures simulating groundwater contaminants, insecticide formulation, and lawn-care herbicides reduced development to blastocyst and mean cell number per embryo (p <or= 0.05). Our data demonstrate that pesticide-induced injury can occur very early in development, with a variety of agents, and at concentrations assumed to be without adverse health consequences for humans.

Agriculture↗
PubMed2004

Association of in utero organophosphate pesticide exposure and fetal growth and length of gestation in an agricultural population.

Although pesticide use is widespread, little is known about potential adverse health effects of in utero exposure. We investigated the effects of organophosphate pesticide exposure during pregnancy on fetal growth and gestational duration in a cohort of low-income, Latina women living in an agricultural community in the Salinas Valley, California. We measured nonspecific metabolites of organophosphate pesticides (dimethyl and diethyl phosphates) and metabolites specific to malathion (malathion dicarboxylic acid), chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridinyl) phosphoro-thioate], and parathion (4-nitrophenol) in maternal urine collected twice during pregnancy. We also measured levels of cholinesterase in whole blood and butyryl cholinesterase in plasma in maternal and umbilical cord blood. We failed to demonstrate an adverse relationship between fetal growth and any measure of in utero organophosphate pesticide exposure. In fact, we found increases in body length and head circumference associated with some exposure measures. However, we did find decreases in gestational duration associated with two measures of in utero pesticide exposure: urinary dimethyl phosphate metabolites [beta(adjusted) = -0.41 weeks per log10 unit increase; 95% confidence interval (CI), -0.75 -- -0.02; p = 0.02], which reflect exposure to dimethyl organophosphate compounds such as malathion, and umbilical cord cholinesterase (beta(adjusted) = 0.34 weeks per unit increase; 95% CI, 0.13-0.55; p = 0.001). Shortened gestational duration was most clearly related to increasing exposure levels in the latter part of pregnancy. These associations with gestational age may be biologically plausible given that organophosphate pesticides depress cholinesterase and acetylcholine stimulates contraction of the uterus. However, despite these observed associations, the rate of preterm delivery in this population (6.4%) was lower than in a U.S. reference population.

Adolescent↗
PubMedDate not supplied

Pesticide removal from container nursery runoff in constructed wetland cells.

The increased use of pesticides by container nurseries demands that practices for removal of these potential contaminants from runoff water be examined. Constructed wetlands may be designed to clean runoff water from agricultural production sites, including container nurseries. This study evaluated 14 constructed wetlands cells (1.2 by 4.9 m or 2.4 by 4.9 m, and 30 or 45 cm deep) that collected pesticide runoff from a 465-m2 gravel bed containerized nursery in Baxter, TN. One-half of the cells were vegetated with bulrush, Scirpus validus. The cells were loaded at three rates or flows of 0.240, 0.120, and 0.060 m3 d(-1). Herbicides-simazine (Princep) [2-chloro-4,6-bis(ethylamino)-s-triazine] and metolachlor (Pennant) [2-chloro-N-(2-ethyl-6-methylphenyl)-N-2-methoxy-1-methylethyl-acetamide] -were applied to the gravel portion of the container nursery at rates of 4.78 and 239 kg ha(-1), respectively, 9 July 1998, and at rates of 2.39 and 1.19 kg ha(-1), respectively, 17 May 1999. Pesticides entering the wetland and wetland cell water samples were analyzed daily to determine pesticide removal. At the slower flow rate, which corresponds to lower mass loading and greater hydraulic retention times (HRTs), a greater percentage of pesticides was removed. During the 2-yr period, cells with plants removed 82.4% metolachlor and 77.1% simazine compared with cells without plants, which removed 63.2% metolachlor and 64.3% simazine. At the lowest flow rate and mass loading, wetland cells removed 90.2% metolachlor and 83% simazine. Gravel subsurface flow constructed wetlands removed most of the pesticides in runoff water with the greatest removal occurring at lower flow rates in vegetated cells.

Agriculture↗
PubMed1993

Organochlorine pesticides in Western Australian nursing mothers.

OBJECTIVES: To measure the concentrations of organochlorine (OC) pesticides in nursing mothers in Western Australia and to evaluate the safety of these concentrations for breast-fed infants; to evaluate the need for future monitoring of OC pesticide concentrations and to determine whether breast milk is an accurate substitute for adipose tissue in future monitoring programs. DESIGN: Two cohorts of nursing mothers were recruited during the period October 1990 to March 1991. Levels of OC pesticides were measured in 128 samples of breast milk and 31 samples each of adipose tissue, maternal blood and cord blood. Laboratory analysis was by gas chromatography with electron capture. Health Department studies since 1974 were collated and levels of OC pesticides compared over time. RESULTS: DDT (dichlorodiphenyltrichloroethane), HCB (hexachlorobenzene) and dieldrin were found in all samples of breast milk and adipose tissue. A significant fall in the levels of OCs was noted since the 1974 survey, with the current concentrations of the cyclodienes (heptachlor, chlordane and dieldrin) being close to the limit of detection of the assay. The acceptable daily intake for dieldrin was exceeded in 90% of infants and for heptachlor in 2% of infants. The daily intakes of the other OCs were below the respective acceptable levels. HCB was detected at a median level of 0.1 mg/kg in both breast milk and adipose tissue despite being deregistered in 1972. As there is no current acceptable daily intake for HCB, the safety of this level could not be assessed by this method. A low correlation was found between levels of the cyclodiene pesticides in breast milk and adipose tissue, but levels of DDT and HCB were closely correlated. CONCLUSIONS: Restrictions on the use of the OC insecticides (DDT, aldrin, dieldrin, heptachlor and chlordane) have resulted in reduced concentrations of these chemicals in breast milk and adipose tissue as compared with previous studies. The dieldrin intake of breast-fed infants consistently exceeded the acceptable daily intake; the heptachlor intake exceeded the acceptable daily intake in some infants, but the low concentrations of heptachlor in breast milk made accurate measurement difficult. The concentrations of DDT and chlordane in breast milk did not pose a hazard to breast-fed infants. The significance of the levels of the fungicide HCB in breast milk cannot be determined. The widespread distribution of HCB, its marked persistence in the environment and its potential for human toxicity indicate a need for continued monitoring, for which breast milk is a suitable medium. The poor correlation between concentrations of dieldrin, heptachlor and chlordane in breast milk and adipose tissue may reflect the technical difficulty of measuring chemical concentrations close to the limit of detection. As aldrin is a registered pesticide and the dieldrin intake of breast-fed infants is consistently above the acceptable daily intake, monitoring of dieldrin should continue. Further population monitoring of DDT, heptachlor and chlordane is unlikely to be of value.

Adipose Tissue↗
PubMed2003

Immunosuppression in the northern leopard frog (Rana pipiens) induced by pesticide exposure.

An injection study and a field study were used to investigate the hypothesis that environmental xenobiotics have the potential to alter the immune function of northern leopard frogs (Rana pipiens). Three assays, IgM-specific antibody response to keyhole limpet hemocyanin linked to dinitrophenyl (KLH-DNP), zymozan induced chemiluminescence (CL) of whole blood and the delayed-type hypersensitivity (DTH), were used to assay humoral, innate and cell-mediated immune endpoints. Sublethal doses of DDT (923 ng/g wet wt), malathion (990 ng/g wet wt), and dieldrin (50 ng/g wet wt) were used in the injection study. In all pesticide-injected groups, antibody response was dramatically suppressed, DTH reactions were enhanced, and respiratory burst was lower. When the order of administration of pesticides and antigens was reversed, no differences in immune function between the control and dosed groups were apparent, indicating that frogs exposed to pathogens prior to pesticide exposure can still respond. A field study found significant differences in immune function between frog populations in pesticide-exposed and pesticide-free locations. The antibody response and CL were suppressed and the DTH enhanced in frogs from Essex County (ON, Canada). Overall, the results suggest that exposure to these pesticides can cause both stimulatory and suppressive immune changes in adult frogs and is doing so in wild populations.

Animals↗
PubMed2003

Organophosphorous pesticides in breast cancer progression.

Environmental substances may be involved in the etiology of breast cancers. Many studies have found an association between cancer in humans and exposure to agricultural pesticides. Organophosphorous pesticides have been used to control mosquito plagues. Parathion and malathion, organophosphorous pesticides are cholinesterase inhibitors responsible for the hydrolysis of body choline esters, including acetylcholine at cholinergic synapses. Their primary target of action in insects is the nervous system whereby they inhibit the enzyme acetylcholinesterase at synaptic junction. Atropine is a parasympatholytic alkaloid used as an antidote to acetylcholinesterase inhibitors. We have established an experimental breast cancer model, where epithelial cells in the rat mammary gland underwent a stepwise transformation into malignant cells by exposure to pesticides (Cabello et al, 2001). The aim of this work was to examine whether pesticides were able to induce progression of malignant transformation of a human breast epithelial cell line, MCF7. These results showed that parathion and malathion increased PCNA and induced mutant p53 protein expression of MCF7 cells in comparison to controls and atropine inhibited such action. These results indicated that organophosphorous pesticides can induce more changes in this malignant breast cell line, inducing another step in the progression of the transformation process and atropine on the other hand inhibited the effect of such substances.

Adenocarcinoma↗
PubMed2005

Human exposure to mosquito-control pesticides--Mississippi, North Carolina, and Virginia, 2002 and 2003.

Public health officials weigh the risk for mosquito-borne diseases against the risk for human exposure to pesticides sprayed to control mosquitoes. Response to outbreaks of mosquito-borne diseases has focused on vector control through habitat reduction and application of pesticides that kill mosquito larvae. However, in certain situations, public health officials control adult mosquito populations by spraying ultra-low volume (ULV) (<3 fluid ounces per acre [oz/acre]) mosquito-control (MC) pesticides, such as naled, permethrin, and d-phenothrin. These ULV applications generate aerosols of fine droplets of pesticides that stay aloft and kill mosquitoes on contact while minimizing the risk for exposure to persons, wildlife, and the environment. This report summarizes the results of studies in Mississippi, North Carolina, and Virginia that assessed human exposure to ULV naled, permethrin, and d-phenothrin used in emergency, large-scale MC activities. The findings indicated ULV application in MC activities did not result in substantial pesticide exposure to humans; however, public health interventions should focus on the reduction of home and workplace exposure to pesticides.

Environmental Exposure↗
PubMed2005

Effects of of habitats and pesticides on aerobic capacity and survival of soil fauna.

OBJECTIVE: Faunal health is largely dependent on their soil environment and available litter quality. So the effects of different soil habitats and pesticides on citrate synthase (CS) activity of soil fauna and its population were studied. METHODS: The soil animals were collected from different pedoecosystems for habitat study. Whereas Vigna radiata based system was selected for pesticidal observations. The field was divided into five equal plots for control and treatment of gamma-BHC, quinalphos, carbaryl and cypermethrin. Soil fauna was collected by quadrat method and extracted by Tullgren funnel. Individuals of a species having similar sizes were collected for the estimation of CS activity. They were homogenized and fractions were obtained by differential centrifugation. The activity of CS was assayed spectrophotometrically. RESULTS: Citrate synthase (CS) activity of beetle (Rasphytus fregi), woodlouse (Porcellio laevis) and centipede (Scolopendra morsitans) varied significantly with respect to changes in different soil habitats. Though the CS activity of R. fregi, P. laevis, and S. morsitans differed among themselves but the highest activity of CS in these animals was in V. radiata and lowest in A. nilotica based pedoecosystem. The aerobic capacity of centipede was maximum followed by woodlouse and beetle. The treatment of gamma-BHC, quinalphos, carbaryl and cypermethrin significantly reduced the CS activity of these animals. Gamma-BHC showed maximum reduction in CS activity indicating highly toxic effect of organochlorine on aerobic metabolism of soil fauna. However, minimum reduction was observed in response to carbaryl (in beetle) or cypermethrin (in woodlouse/centipede) leading to impairment of aerobic capacity. The differences in pesticide effects might be assigned to the differences in chemical nature of pesticides and their interactions with below-ground fauna. Treatment of gamma-BHC and quinalphos reduced the population of Acari, Coleoptera, Collembola, other arthropods as well as total soil fauna. Acari was least affected by gamma-BHC and maximally affected (72%) in response to quinalphos. The effect of gamma-BHC was fairly similar on Coleoptera, Collembola, other arthropod and total soil fauna suggesting almost similar sensitivity to this pesticide. Likewise, quinalphos was similarly effective on Collemobola and other soil arthropods. Application of carbaryl decreased Acari and Coleoptera population but increased Collembola, other arthropods and total faunal populations. However, application of cypermethrin significantly reduced the population of Acari, Coleoptera, Collembola and total soil fauna and increased the population of other soil arthropods. In both the cases, acarine population was least affected. CONCLUSION: The observations show the habitat-specific variation in aerobic capacity of soil fauna. However, pesticide-dependent loss in population might be due to impairment of aerobic capacity of soil inhabiting animals in desert.

Animals↗
PubMedDate not supplied

Rapid determination of organochlorine pesticides and polychlorinated biphenyls, using selected ion monitoring mass spectrometry.

Methane chemical ionization (CI)-selected ion monitoring (SIM) mass spectrometry was used to identify and conclusively distinguish 19 organochlorine pesticides from polychlorinated biphenyls (PCBs) at parts-per-trillion to parts-per-billion levels in environmental water sample extracts with minimal sample cleanup. Two CI-SIM screens were developed. One set of ions scanned specifically for the presence of 4 classes of pesticides: diphenylmethane derivatives, bridged polycyclic chlorinated hydrocarbons, chlorinated benzenes, and acetanilide pesticides. The second set of ions responded exclusively to PCBs with biphenyl moieties containing from 1 to 8 chlorine atoms. Eight commercial Aroclor mixtures were analyzed and distinguished from the pesticide groups. The detection limit for pesticides and PCBs by CI-SIM screening was 0.005 and 0.1 ppb, respectively. CI-SIM can be used as an alternative method for the analysis of biological or environmental samples containing interferences that complicate the detection of PCBs and chlorinated pesticides.

Fresh Water↗