Association of Long-Term Pesticide Exposure and Biologic Parameters in Female Farm Workers in Tanzania: A Cross Sectional Study

Comparison of Biochemical, Haematological and Plasmatic Butyrylcholinesterase Parameters in Farmers and Non-Farmers, Morocco

Background

The long-term use of pesticides can cause harmful consequences to both human health and the environment. In the present research, we aimed to compare biochemical, hematological, and plasmatic measurements of butyrylcholinesterase (BChE) between farmers and non-farmers.

Materials and Methods

The study is cross-sectional and included 270 participants, with 135 farmers using pesticides and a control population of 135 non-farmers. The recruitment of the participants was conducted from August 2017 to the end of December 2019. Blood samples from participants were collected for the evaluation of biochemical markers of the function of the liver and determination of BChE activity. A whole blood sample with ethylenediamine tetraacetic anticoagulant (EDTA) was also taken for a complete blood count.

Results

The results showed a statistically significant (P = 0.03) decrease in mean corpuscular hemoglobin (MCH) in the cases (28.45 ± 2.94 pg) as compared with controls (29.17 ± 2.54 pg). The statistical analysis of the renal parameters between the two groups determined that the uremia value was significantly higher in cases (34 ± 12 mg/dL) when compared to the control group (29 ± 8 mg/dL) P < 0.001. The cases recorded a significant increase in aspartate aminotransferase (AST) (26.22 ± 11.59 U/L) and alanine aminotransferase (ALT) (25.63 ± 13.47 U/L) enzyme activities among cases versus controls. The results obtained showed a significantly decreased BChE activity in the group of cases exposed to pesticides (7554.52 ± 2107 U/l) compared to the unexposed control group (10135.58 ± 1909 U/l) (t-test, P < 0.001).

Conclusion

The education of the farmers on correct practices concerning phytosanitary use has the potential of reducing their exposure to these products.

Mechanistic investigation of the differential synergistic neurotoxicity between pesticide metam sodium and copper or zinc

Epidemiological studies suggest neurological disorders have been associated with the co-exposure to certain pesticides and transition metals. The present study aims to investigate whether co-exposure to the widely-used pesticide metam sodium and copper (Cu²⁺) or zinc ion (Zn²⁺) is able to cause synergistic neurotoxicity in neural PC12 cells and its possible mechanism(s). We found that both metam/Cu²⁺ and metam/Zn²⁺ synergistically induced apoptosis, intracellular Cu²⁺/Zn²⁺ uptake, reactive oxygen species (ROS) accumulation, double-strand DNA breakage, mitochondrial membrane potential decrease, and nerve function disorder. In addition, metam/Cu²⁺ was shown to release cytochrome c and apoptosis-inducing factor (AIF) from mitochondria to cytoplasm and nucleus, respectively, and activate the caspase 9, 8, 3, 7. However, metam/Zn²⁺ induced caspase 7 activation and AIF translocation and mildly activated cytochrome c/caspase 9/caspase 3 pathway. Furthermore, metam/Cu²⁺ activated caspase 3/7 by the p38 pathway, whereas metam/Zn²⁺ did so via both the p38 and JNK pathways. These results demonstrated that metam/Cu²⁺ or metam/Zn²⁺ co-exposure cause synergistic neurotoxicity via different mechanisms, indicating a potential risk to human health when they environmentally co-exist.

The association between blood, urine, respiratory, neurobehavioral parameters and occupational exposure to organophosphorus pesticides: a cross-sectional study among formulators

Background

Organophosphate (OP) pesticides are one of the most extensively used chemical compounds all over the world.

Objective

The aim of this study is to determine whether occupational exposure of the formulators to the OP pesticides, under normal working conditions, is associated with any hematotoxic, hepatotoxic, nephrotoxic, neurotoxic, and respirotoxic responses among them.

Methods

28 OP formulation plant workers and 17 office workers participated in this cross-sectional study as the exposed and control groups, respectively. Blood and urine samples were collected to measure hematological, biochemical, and urinalysis parameters. American thoracic society questionnaire and spirometry tests were employed to assess the function of their respiratory system. Q16 questionnaire was also used to investigate the prevalence of neurobehavioral symptoms. The data were analyzed by SPSS v.22 software using Kolmogorov-Smirnov, T-test, Mann-Whitney U, Chi-square, Fisher, Pearson, and Spearman tests.

Results

No statistically significant difference was found in hematological, biochemical, urinalysis (except in specific gravity), spirometry parameters, as well as respiratory and neurobehavioral symptoms between the exposed and the control groups. For the exposed group, however, the means of spirometry parameters were significantly lower among the smokers.

Conclusions

In this study, the expected adverse health effects due to exposure to OP pesticides were not observed among the formulators; however, the risk of developing respiratory dysfunction was found to be more considerable among smoker subjects than the non-smoker ones. Further investigations are required to determine whether formulators' occupational exposures to OP pesticides result in certain adverse health effects.

Association between Haematological Parameters and Exposure to a Mixture of Organophosphate and Neonicotinoid Insecticides among Male Farmworkers in Northern Thailand

Exposure to insecticides may result in various health problems. This study investigated the association between haematological parameters and exposure to a mixture of organophosphate (OP) and neonicotinoid (NEO) insecticides among male farmworkers in Fang district, Chiang Mai province, northern Thailand. Concentrations of urinary dialkylphosphates, non-specific metabolites of OPs, and NEOs and their metabolites and haematological parameters were measured in 143 male farmworkers. The Bayesian kernel machine regression model was employed to evaluate the associations. Exposure to a mixture of insecticides was significantly associated with the mean corpuscular haemoglobin concentration (MCHC) when the concentrations of all the compounds and their metabolites were at the 60th percentile or higher compared with the 50th percentile. Furthermore, exposure to clothianidin (CLO) showed a decreasing association with MCHC when all the other insecticides were at their mean concentrations. CLO was the most likely compound to reduce MCHC, and this was confirmed by sensitivity analysis. These findings suggest that exposure to NEO insecticides, especially CLO, affects the haematological status relating to haemoglobin parameters.

Measuring butyrylcholinesterase activity and hematological parameters in farmers exposed to pesticides: a case and control study from Morocco

The Farmers are exposed to a wide range of pesticides. The application of these pesticides has been documented to lead to several adverse health effects. This aim of this case-control study was to estimate risks linked to pesticide exposure among farmers in the Souss region of Morocco through the analysis of serum butyrylcholinesterase (BChE) activity and hematological parameters. This prospective study included 98 participants (49 farmers and 49 controls). A questionnaire was used to collect socio-demographic data, technical information regarding the application of pesticides, previous poisonings by pesticides, and training on the use of pesticides. The blood samples were collected for hematological parameters and BChE analysis, and the activity of BChE was measured spectrophotometrically by the butyrlthiocholine method. The results showed no significant differences in hemoglobin (HB), hematocrit, mean corpuscular volume, platelets, red blood cell, and leukocyte cell counts between both the exposed farmer and the control group. In contrast, a significant decreased in mean corpuscular HB, mean corpuscular HB concentration, eosinophils, and basophils counts were observed. In addition, the exposed group showed a significant decrease in the BChE activity (p < .001) compared to the control group. Farmers exposed to pesticides in the Souss Massa region may be at risk of hematological alterations as well as neurotoxicity, characterized by inhibition of BChE enzyme activity.

General and reproductive health outcomes among female greenhouse workers: a comparative study

Background

Agricultural activities as well as exposure to pesticides could have many adverse effects on health status and reproductive outcomes especially in reproductive aged greenhouse workers. The present study aimed to compare the general and reproductive health outcomes between female greenhouse workers and housewives.

Methods

This cross-sectional study was conducted on 645 females of reproductive age. They were categorized into two groups according to occupation in greenhouse (308 female greenhouse workers as exposed group and 337 housewives as control group). Participants were interviewed using a questionnaire about reproductive outcomes and occupational status. Clinical measures include blood pressure (BP), pulse and respiratory rate (PR and RR), body mass index (BMI) and hematological parameters. Mann-Whitney U test was used to assess differences between two groups in quantitative variables. Chi-square or Fisher’s exact tests was used to determine the differences in the distribution of categorical variables. Data was analyzed using SPSS software version 16.

Results

The average daily working hours of the greenhouse workers were 6.94 ± 1.99 h. Only 44.3% of them used personal protective equipment. Data revealed that the rate of spontaneous abortion, infertility, low birth weight (LBW), abnormal births and preterm birth were significantly higher among the greenhouse workers compared to the control group (p ≤ 0.05). The average number of female infants in greenhouse workers was significantly higher than the control group (p ≤ 0.05). Clinical measurements indicated an increase in RR of greenhouse workers and mean of BMI was decreased in them. Hematological parameters demonstrated that there was a significant increase in white blood cells (WBC) and significant decrease in hemoglobin (Hb), hematocrit (HCT), mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC) among the female greenhouse workers compared to the control (p ≤ 0.05).

Conclusion

Local government efforts is needed to address associated issues including acute effects on health and long-term health risks, resulting from pesticide exposure to greenhouse workers, and gender differences should be considered. Also, occupational health and safety training is necessary and can be helpful in reducing adverse reproductive outcomes.

Environmental Health Research in Africa: Important Progress and Promising Opportunities

The World Health Organization in 2016 estimated that over 20% of the global disease burden and deaths were attributed to modifiable environmental factors. However, data clearly characterizing the impact of environmental exposures and health endpoints in African populations is limited. To describe recent progress and identify important research gaps, we reviewed literature on environmental health research in African populations over the last decade, as well as research incorporating both genomic and environmental factors. We queried PubMed for peer-reviewed research articles, reviews, or books examining environmental exposures and health outcomes in human populations in Africa. Searches utilized medical subheading (MeSH) terms for environmental exposure categories listed in the March 2018 US National Report on Human Exposure to Environmental Chemicals, which includes chemicals with worldwide distributions. Our search strategy retrieved 540 relevant publications, with studies evaluating health impacts of ambient air pollution (n=105), indoor air pollution (n = 166), heavy metals (n = 130), pesticides (n = 95), dietary mold (n = 61), indoor mold (n = 9), per- and polyfluoroalkyl substances (PFASs, n = 0), electronic waste (n = 9), environmental phenols (n = 4), flame retardants (n = 8), and phthalates (n = 3), where publications could belong to more than one exposure category. Only 23 publications characterized both environmental and genomic risk factors. Cardiovascular and respiratory health endpoints impacted by air pollution were comparable to observations in other countries. Air pollution exposures unique to Africa and some other resource limited settings were dust and specific occupational exposures. Literature describing harmful health effects of metals, pesticides, and dietary mold represented a context unique to Africa. Studies of exposures to phthalates, PFASs, phenols, and flame retardants were very limited. These results underscore the need for further focus on current and emerging environmental and chemical health risks as well as better integration of genomic and environmental factors in African research studies. Environmental exposures with distinct routes of exposure, unique co-exposures and co-morbidities, combined with the extensive genomic diversity in Africa may lead to the identification of novel mechanisms underlying complex disease and promising potential for translation to global public health.

Health problems from pesticide exposure and personal protective measures among women cotton workers in southern Pakistan

Women are the main cotton pickers in Pakistan even from their childhood, but due to unawareness of pesticide risks and poor knowledge of personal protection opportunities, they typically do not use personal protective measures. Albeit a major agricultural topic in Pakistan, relevant research is limited. The present study illustrates health problems from pesticide exposure during cotton harvest and the use of personal protective measures among 260 female cotton-picking workers from Shaheed Benazirabad District of Sindh Province in southern Pakistan. Skin injury, eye injury, headache, stomachache, and fever were the main health problems due to pesticide exposure according to workers' experience. Medical treatment costs of health problems were more than double (2.48 times higher) than preventive measures costs. More than half of the cotton workers surveyed did not use any protective measure during cotton picking, while 22.3% used a muffler/scarf/cloth for covering their face and 10.8% used gloves. Covering face with muffler/scarf/cloth was higher in young (P < 0.05), married (P < 0.05), and high experienced workers (P < 0.05), while no significant trends were found in the use of gloves. The use of protective measures was positively correlated with education and some experience in cotton picking. Binary logit regression showed that advanced age and high picking experience were positively associated with the use of personal protective measures, while illiteracy, traditional treatment, and medical treatment in case of illness were negatively associated with the use of personal protective measures. Findings shed new light on the topic of personal safety among women cotton pickers in Pakistan. Increasing formal education and implementing training programs for personal protective measures are important to reduce health risk and health cost by pesticides among women workers.

Non-target toxicity of novel insecticides

Humans have used insecticides since ancient times. The spectrum and potency of available insecticidal substances has greatly expanded since the industrial revolution, resulting in widespread use and unforeseen levels of synthetic chemicals in the environment. Concerns about the toxic effects of these new chemicals on non-target species became public soon after their appearance, which eventually led to the restrictions of use. At the same time, new, more environmentally-friendly insecticides have been developed, based on naturally occurring chemicals, such as pyrethroids (derivatives of pyrethrin), neonicotinoids (derivatives of nicotine), and insecticides based on the neem tree vegetable oil (Azadirachta indica), predominantly azadirachtin. Although these new substances are more selective toward pest insects, they can still target other organisms. Neonicotinoids, for example, have been implicated in the decline of the bee population worldwide. This review summarises recent literature published on non-target toxicity of neonicotinoids, pyrethroids, and neem-based insecticidal substances, with a special emphasis on neonicotinoid toxicity in honeybees. We also touch upon the effects of pesticide combinations and documented human exposure to these substances.

Health effects associated with occupational exposure to hand-arm or whole body vibration

Workers in a number of different occupational sectors are exposed to workplace vibration on a daily basis. This exposure may arise through the use of powered-hand tools or hand-transmitted vibration (HTV). Workers might also be exposed to whole body vibration (WBV) by driving delivery vehicles, earth moving equipment, or through use of tools that generate vibration at low dominant frequencies and high amplitudes, such as jackhammers. Occupational exposure to vibration has been associated with an increased risk of musculoskeletal pain in the back, neck, hands, shoulders, and hips. Occupational exposure may also contribute to the development of peripheral and cardiovascular disorders and gastrointestinal problems. In addition, there are more recent data suggesting that occupational exposure to vibration may enhance the risk of developing certain cancers. The aim of this review is to provide an assessment of the occupations where exposure to vibration is most prevalent, and a description of the adverse health effects associated with occupational exposure to vibration. This review will examine (1) various experimental methods used to measure and describe the characteristics of vibration generated by various tools and vehicles, (2) the etiology of vibration-induced disorders, and (3) how these data were employed to assess and improve intervention strategies and equipment that reduces the transmission of vibration to the body. Finally, there is a discussion of the research gaps that need to be investigated to further reduction in the incidence of vibration-induced illnesses and injuries.