A preliminary study of immunologic and hematologic profiles of peripheral blood from Nebraska farmers who apply pesticides to their fields

Occupational exposure to pesticides and hematological alterations: A survey of farm residents in the South of Brazil

Abstract This study sought to investigate the association of exposure to organochlorine (OC) and non-persistent pesticides with hematological parameters in an agricultural population in Southern Brazil. A cross-sectional study was conducted with a random sample of 275 farm workers and their families in Farroupilha-RS. A questionnaire was used to collect information on sociodemographic and lifestyle factors, duration, frequency and type of pesticide used, among others. Blood samples were collected and analyzed for serum concentration of 24 OC pesticides and hematological parameters. Associations were explored through linear regression, controlling for confounders. Lifetime use of chemical classes other than organophosphates and dithiocarbamates were associated with decreased number of lymphocytes, while subjects sampled in the high pesticide use season showed higher number of erythrocytes and hemoglobin level. Detectable serum levels of many OC pesticides were associated with lower counts of white blood cells, particularly eosinophils. Although mostly null associations were observed between pesticide use and hematological parameters, findings may suggest that OC pesticides could lead to hematological alterations among agricultural workers.

Differential expression profile of membrane proteins in Aplysia pleural–pedal ganglia under the stress of methyl parathion

This study was aimed to analyze the alteration of membrane protein profiles in Aplysia juliana Quoy & Gaimard (A. juliana) pleural–pedal ganglia under MP exposure. Both the results of GC–MS analysis and the activity assay of acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT) reveal that MP toxicological effects on Aplysia left and right pleural–pedal ganglia are different under 7 and 14 days of exposure. Therefore, Aplysia were subjected for exposure at two concentrations (1 and 2 mg/l) of MP for 7 and 14 days for membrane proteomic study. As a result, 19 and 14 protein spots were differentially expressed in A. juliana left pleural–pedal ganglia under 7 and 14 days treatment, and 20 and 14 protein spots found with differential expressions in their right ganglia under the same treatment, respectively. Several proteins with expression variations were detected from both the left and right pleural–pedal ganglia; however, most proteins have distinctive expressions, indicating different mechanisms might be involved in initiating MP toxicology in left and right ganglia. Among the total differential protein spots obtained, 29 proteins were classed as membrane proteins. These proteins are mainly involved in the metabolism process, cell redox homeostasis, signal transduction, immunology, intracellular transport and catalysis, indicating MP toxicity in mollusks seems to be complex and diverse. Some differentially expressed proteins were further confirmed by Western blotting and quantitative real-time PCR. These results might provide renovated insights to reveal the mechanism of MP-induced neurotoxicity, and the novel candidate biomarkers might have potential application for environmental evaluation of MP pollution level.

Lifetime pesticide use and telomere shortening among male pesticide applicators in the Agricultural Health Study

BACKGROUND

Telomere length (TL) in surrogate tissues may be influenced by environmental exposures.

OBJECTIVE

We aimed to determine whether lifetime pesticides use is associated with buccal cell TL.

METHODS

We examined buccal cell TL in relation to lifetime use of 48 pesticides for 1,234 cancer-free white male pesticide applicators in the Agricultural Health Study (AHS), a prospective cohort study of 57,310 licensed pesticide applicators. Participants provided detailed information on lifetime use of 50 pesticides at enrollment (1993-1997). Buccal cells were collected from 1999 to 2006. Relative telomere length (RTL) was measured using quantitative real-time polymerase chain reaction. We used linear regression modeling to evaluate the associations between specific pesticides and the logarithm of RTL, adjusting for age at buccal cell collection, state of residence, applicator license type, chewing tobacco use, and total lifetime days of all pesticide use.

RESULTS

The mean RTL for participants decreased significantly in association with increased lifetime days of pesticide use for alachlor (p = 0.002), 2,4-dichlorophenoxyacetic acid (2,4-D; p = 0.004), metolachlor (p = 0.01), trifluralin (p = 0.05), permethrin (for animal application) (p = 0.02), and toxaphene (p = 0.04). A similar pattern of RTL shortening was observed with the metric lifetime intensity-weighted days of pesticide use. For dichlorodiphenyltrichloroethane (DDT), we observed significant RTL shortening for lifetime intensity-weighted days (p = 0.04), but not for lifetime days of DDT use (p = 0.08). No significant RTL lengthening was observed for any pesticide.

CONCLUSION

Seven pesticides previously associated with cancer risk in the epidemiologic literature were inversely associated with RTL in buccal cell DNA among cancer-free pesticide applicators. Replication of these findings is needed because we cannot rule out chance or fully rule out bias.

Effect of vitamin e supplementation on biochemical parameters in pesticides sprayers of grape gardens of Western maharashtra (India)

The aim of this study was to see the biochemical effects of pesticides on sprayers of grape gardens before and after 15 days of vitamin E supplementations in Western Maharashtra (India), who were occupationally exposed to various pesticides over a long period of time (about 5 to 15 years). Blood samples were collected from all study group subjects for biochemical parameters assays before and after 15 days of vitamin E supplementation. Sprayers of grape gardens were given 400 mg of vitamin E tablet/day for 15 days. After 15 days of vitamin E supplementation to sprayers of grape gardens, we observed significantly decreased aspartate transaminase (10.88 %, P < 0.05, r = 0.88), alanine transaminase (25.92 %, P < 0.01, r = 0.46) and total proteins (3.32 %, P < 0.01, r = 0.33), whereas, no statistically significant change was found in serum acetyl cholinesterase, C-reactive proteins, albumin (ALB), globulins and ALB/globulin ratio as compared to before vitamin E supplementation. Sprayers of grape gardens, who received vitamin E supplementation, showed significantly decreased serum lipid peroxide (LP) (18.75 %, P < 0.001, r = 0.63) and significantly increased RBC-superoxide dismutase (SOD) (12.88 %, P < 0.001, r = 0.85), RBC-Catalase (CAT) (24.49 %, P < 0.001, r = 0.70), plasma ceruloplasmin (CP) (4.6 %, P < 0.01, r = 0.80), serum zinc (4.57 %, P < 0.01, r = 0.83) and serum copper (4.37 %, P < 0.01, r = 0.79) as compared to values before vitamin E supplementation. These results showed that vitamin E supplementation has ameliorating effects on these transaminase enzymes, suggesting that it may have a protective effect on liver, from pesticides induced damage. In this study vitamin E supplementation might have decreased LP levels by breaking chain reaction of lipid peroxidation. Present results indicate that vitamin E plays a crucial role in restoring the antioxidant enzymes such as SOD, CAT and CP, in population exposed to pesticides. This helps to enhance its antioxidant ability. Therefore, it is suggested that farmers, pesticide applicators, workers in the pesticide industry and other pesticide users, who come in regular contact with pesticides, may be benefited by supplementation with vitamin E.

Pesticide exposure, risk factors and health problems among cutflower farmers: a cross sectional study

This was a cross-sectional study which aimed to determine associations between hematologic indices such as red blood cell cholinesterase (RBC) and mean corpuscular volume (MCV), with illnesses related to pesticide exposure among cutflower farmers in La Trinidad, Benguet. One hundred two (102) randomly selected cutflower farmers underwent comprehensive, personal physical health and laboratory examinations and answered a questionnaire on work practices and illness. Majority were males (52%) and most belonged to the 20–35 age group (45%). Majority of exposed farmers were symptomatic, with most common complaints being headache (48%), easy fatigability (46.1%) and cough (40.2%). Analysis showed that RBC cholinesterase levels were positively associated with age (p = 0.02), and selling pesticide containers (p = 0.008). number of years of using pesticides (p = 0.022), use of contaminated cloth (p = 0.033), incorrect mixing of pesticides (p = 0.041), sex (p = 0.002) and illness due to pesticides (p = 0.005) were correlated with abnormal MCV. Significant associations were also found for hemoglobin, hematocrit, RBC, white blood cell (WBC) and platelet count. Predictors of RBC cholinesterase were years of pesticide use (p = 0.037) and abnormalities on health (p = 0.029). The findings of the study can be used for information dissemination and pesticide reduction programs for the cutflower farmers.

Fetal deaths and proximity to hazardous waste sites in Washington State

BACKGROUND

The in utero period is one of increased susceptibility to environmental effects. The effects of prenatal exposure to environmental toxicants on various adverse pregnancy outcomes, including fetal death, are not well understood.

OBJECTIVE

We examined the risk of fetal death in relation to maternal residential proximity to hazardous waste sites.

METHODS

We conducted a population-based case-control study using Washington State vital records for 1987-2001. Cases were women with fetal deaths at > or = 20 weeks (n = 7,054). Ten controls per case were randomly selected from live births. Locations of 939 hazardous waste sites were identified from the Department of Ecology registry. We measured distance from maternal residence at delivery to the nearest hazardous waste site, and calculated odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The risk of fetal death for women residing < or = 0.5 miles, relative to > 5 miles, from a hazardous waste site was not increased (adjusted OR = 1.06; 95% CI, 0.90-1.25). No associations were observed for any proximity categories < or = 5 miles from sites with contaminated air, soil, water, solvents, or metals; however, fetal death risk increased among women residing < or = 1 mile from pesticide-containing sites (OR = 1.28; 95% CI, 1.13-1.46).

CONCLUSION

These results do not suggest that fetal death is associated with residential proximity to hazardous waste sites overall; however, close proximity to pesticide-containing sites may increase the risk of fetal death.

Adverse health effects of children's exposure to pesticides: what do we really know and what can be done about it

Children may be exposed to pesticides in several ways, such as by transplacental transfer during foetal life, by intake of contaminated breast milk and other nutrients, or by contact with contaminated subjects and areas in the environment such as pets treated with insecticides, house dust, carpets and chemically treated lawns and gardens. Exposure early in life, and particularly during periods of rapid development, such as during foetal life and infancy, may have severe effects on child health and development by elevating the risk of congenital malformations, cancer, malabsorption, immunological dysfunction, endocrine disease, and neurobehavioural deficiencies. As pesticides can also interfere with parental reproductive health, exposure of parents may have consequences for the offspring leading to reduced chance of male birth and increased risk of childhood cancer.

CONCLUSIONS

Current knowledge about tolerable levels and consequences of toxic exposure to pesticides during human development is rather scarce. Owing to the high risk of exposure to pesticides, particularly in less developed countries, further elucidation by well-controlled epidemiological studies in this field it is urgently needed. The Policy Interpretation Network on Children's Health and Environment (PINCHE), which is financed by the EU DG research has suggested actions against pesticide exposure. They have been presented and discussed in this paper. Several suggestions of PINCHE concerning action needed regarding pesticides were presented in the paper.

Methyl-parathion and organophosphorous pesticide metabolites modify the activation status and interleukin-2 secretion of human peripheral blood mononuclear cells

Organophosphorous (OP) compounds are the most commonly used pesticides. There are reports on susceptibility to the toxic effects of OP pesticides, but no information exists regarding the toxicity of their metabolites. To determine the metabolites' contribution to the OP pesticide immunotoxic effects, human peripheral blood mononuclear cells (PBMCs) were treated with the parent compound methyl-parathion (MP) and the following OP pesticide alkyl-phosphorous metabolites: diethylphosphate (DEP), diethylthiophosphate (DETP), diethyldithiophosphate (DEDTP), dimethylphosphate (DMP), and dimethyldithiophosphate (DMDTP). Activation and function of the PBMCs were examined by assessment of phytohemagglutinin (PHA)-induced proliferative response, interleukin-2 (IL-2) secretion, and CD25 and CD69 expression. Treatments with DMP, DEP, DETP and DEDTP for 48h produced significant toxicity in human PBMCs, but did not affect their proliferative response to PHA. Only MP reduced cell proliferation by 30%. DEDTP decreased the proportion of PBMCs expressing CD25. This effect was associated with a reduction of IL-2 secretion, which was also reduced by MP and DMP treatments. In contrast, DETP and DEDTP treatments increased the expression of CD69. DMP, DETP and DEDTP were more consistently involved in modulating the PBMC response to PHA.

Micronucleus frequency and proliferation in human lymphocytes after exposure to herbicide 2,4-dichlorophenoxyacetic acid in vitro and in vivo

Widespread use of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and its association with non-Hodgkin's lymphoma (NHL) and other cancers has raised public concern. Here, micronucleus (MN) formation has been used as a biomarker of genotoxicity, and replicative and mitotic indices (MIs) as biomarkers of cell cycle kinetics in human lymphocytes. Cells were cultured either as whole blood or isolated lymphocytes and treated with pure or commercial forms of 2,4-D at doses between 0.001 and 1 mM for 48 h. Exposure to 2,4-D produced a minimal increase in MN in whole blood and even smaller one in isolated lymphocyte cultures. This induction took place only at levels approaching cytotoxicity and was accompanied by a significant inhibition of replicative index (RI). At a low (0.005 mM) dose of commercial 2,4-D, a small, marginally significant increase in RI (12-15%) was found in two independent sets of experiments (P=0.052). Additionally, we found that lymphocyte RI was more affected by commercial 2,4-D containing 9.4% of the chemically pure 2,4-D, than with an equal concentration of the latter suggesting that other ingredients present in the commercial pesticide may be responsible or may enhance the effect of 2,4-D. Mitotic index, however, did not show any significant change with either commercial or pure 2,4-D. The lymphocytes of 12 male applicators exposed solely to 2,4-D during a 3-month period had a significantly higher RI than the same group prior to exposure and than a control group (P<0.01), in accordance with the in vitro finding of increased RI at low doses.

Vitamin E supplementation on biochemical changes observed in agricultural field workers exposed to different classes of pesticides

A total of 41 healthy male pesticide sprayers exposed to different clases of pesticides for 3-5 years were compared with 21 controls matched for age and economic status with respect to free radical generation, lipid peroxidation, antioxidant status, cholesterol, lipoprotein status and haematological profile. Plasma lipid peroxidation was estimated in the form of thiobarbituric acid reactive substances (TBARS) produced. Significant increase in TBARS was observed in sprayers population when compared with control subjects and the level of TBARS increased with increase in the duration of exposure. The levels of antioxidants such as glutathione (GSH) were significantly depleted, whereas those of superoxide dismutase (SOD) were remarkably increased than control population. Significant reduction in total cholesetrol, alteration in lipoprotein fractions and nonsignificant changes in hematological parameters were observed. These results suggested that exposure to pesticidal residual drift augments the free radical generation, and lipid peroxidation. Decline in non-enzymatic antioxidant and elevation of enzymatic antioxidant were observed. Supplementation of α-tocopherol for 45 days resulted in the partial restoration of these biochemical changes produced by pesticides.