Effect of Pesticide Exposure on Immunological, Hematological and Biochemical Parameters in Thai Orchid Farmers— A Cross-Sectional Study

Abstract

Various studies have found that many Thai orchid farmers used excessive amounts of pesticides without proper protective gear, but no toxicological study has been made. This cross-sectional study aimed to evaluate the immunological, hematological and biochemical statuses of these farmers. Sixty four orchid farmers and 60 controls were studied. Plasma cholinesterase activity, the percentage and absolute number of B lymphocytes (CD19+) were significantly lower in the farmers group (3966.32 ± 1165.48 U/L, 11.61 ± 4.09% and 312.26 ± 164.83 cells/mm3, respectively) as compared to those of controls (5048.85 ± 1139.40 U/L, 14.32 ± 4.23%, 420.34 ± 195.18 cells/mm3, respectively). There was a statistically significant higher level of serum IgE among the orchid farmers (0.031 ± 0.011 mg/dL vs. 0.018 ± 0.007 mg/dL) but not IgG, IgA and IgM, levels. Serum lysozyme level, lymphocyte proliferative responses to mitogens, hematological parameters and kidney function test, were not significantly different between the two groups. The liver function profiles showed significantly lower levels of albumin and serum protein in the farmer group. Thus frequent pesticide exposure resulted in subtle changes of some biological parameters. These changes, though may not be clinically significant, strongly indicated that caution in handing pesticides by these farmers is warranted.

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

“…Results from the current report regarding pesticide use and hematological parameters are consistent with previous studies which failed to reveal a consistent relationship between pesticide exposure and hematological parameters among farmers 21,27,28 . Thus, a Thai study with orchid farmers found no significant differences in hematological parameters between subjects highly exposed to pesticides and non-exposed subjects 21 .…”

“…Results from the current report regarding pesticide use and hematological parameters are consistent with previous studies which failed to reveal a consistent relationship between pesticide exposure and hematological parameters among farmers 21,27,28 . Thus, a Thai study with orchid farmers found no significant differences in hematological parameters between subjects highly exposed to pesticides and non-exposed subjects 21 . An Egyptian study only found increased leukocyte count in farmers compared to non-ex- 27 , while an Indian study observed decreased leukocytes count in pesticide-exposed workers vs. unexposed individuals but no significant differences in erythrocytes, hemoglobin, and others hematological parameters 28 .…”

“…Agricultural populations in developing countries are exposed to increasing amounts of pesticides mixtures, at high concentrations and frequency, including pesticides severely restricted and banned in industrialized countries 21 . We have previously reported associations of cumulative exposure to pesticides, especially herbicides and dithiocarbamate fungicides, with hypothyroidism-like effects and poorer sperm quality in male farm workers in Serra Gaúcha, a family-based agricultural region in the South of Brazil 22,23 .…”

Biochemical Changes Associated with Long Term Exposure to Pesticide among Farmers in the Gaza Strip

“…Our suggestion is supported by the data in Table 8 which showed increased visits to different clinics due to long term exposure to pesticides. More supports come from Sarhan and Al-Sahhaf [48] and Aroonvilairat et al [49], who showed lower levels of serum proteins and increase in creatinine and blood urea and renal damage among farmers exposed to organophosphourus insecticides. Moreover, the increased number of farmer visits to hospital or private clinics indicates the progressive toxicity increase.…”

Altered Hematological and Biochemical Parameters in Schoolchildren Living in an Agricultural Community of Merida State, Venezuela

“…Various studies on animal models exposed to specific pesticides have explored changes in hematological and biochemical parameters as possible biomarkers of pesticide exposure before adverse clinical health problems occur [24][25][26][27][28][29]. More recently, clinical studies on pesticide sprayers have focused on the immunological, hematological and biochemical statuses of these farmers [23,[67][68][69][70][71]. However, to our knowledge, there are no published reports on biomonitoring of children living in an agricultural community, where there is a high risk of exposure to the toxic effects of pesticides.…”