Pesticide Application and Khat Chewing as Predictors of the Neurological Health Outcomes among Pesticide Applicators in a Vector Control Unit, Saudi Arabia

Neurobehavioral Effects of Low-Dose Chronic Exposure to Insecticides: A Review

The modes of action of insecticides frequently involve a neurotoxic effect; therefore, the study of neurotoxic effects caused by long-term and low-dose insecticide exposure is of particular interest. This study looks at whether or not new studies conducted after 2009 and up to 2021 have provided new evidence for a better understanding of the actual neurobehavioral risk associated with long-term insecticide exposure. We selected and reviewed studies carried out on the neurobehavioral effects of neurotoxic insecticides (organophosphates and/or carbamates, pyrethroids, multiple or undefined insecticides, and organochlorines) considering occupational and non-occupational exposures. The articles were also scored and ranked based on seven parameters. Eighty-six studies were chosen for a final review process from among the 950 scientific papers identified. Twenty-six addressed occupational exposure and six environmental exposure. Among the latter group of studies, 17 focused on rural residents, to be assumed exposed because of living in rural areas, and 43 on the general population. Pending doubts have not been resolved in the last ten years due to the presence of contradictory and hardly comparable results and the fact that in most of the studies showing an evident neurobehavioral impairment the frequent presence of a previous episode of poisoning and hospitalization, with severe brain hypoxia, impaired the possibility of confirming the presence of a causal association with insecticide exposure. Interestingly, the most severely exposed groups, such as applicators who did not wear personal protective equipment, performed worse on neurobehavioral tests. As for residential exposure, there is sufficient evidence to suggest that prenatal OP exposure may increase the risk of ADHD in children.

Neurobehavioral, Neuromotor, and Neurocognitive Effects in Agricultural Workers and Their Children Exposed to Pyrethroid Pesticides: A Review

In recent years, pyrethroids have emerged as a less toxic alternative to eliminate insect pests. However, some animal studies and studies with children show that these pesticides are toxic and lead to neurobehavioral effects similar to other pesticides, such as organophosphates. The purpose of this review was to systematize the epidemiological scientific evidence about the neurobehavioral, neuromotor, and neurocognitive effects in agricultural workers and their children exposed to pyrethroid pesticides. We conducted two searches (with different terms) in PubMed and Scopus databases, including articles in Spanish and English language on the effects of occupational exposure to pyrethroid pesticides associated with neurobehavioral, neuromotor, and neurocognitive functioning of agricultural workers and their children. There were no filters by year, and the search included studies till march 2021. To develop the search, we followed the recommendations contained in the PRISMA guidelines and the PICO strategy. The results show that in 66.6% of the studies reviewed (8 of 12 studies), agricultural workers or their children occupationally exposed to pyrethroid pesticides have a higher risk of presenting difficulties in their neurocognitive, neuromotor, or neurobehavioral performance, mainly associated with attention, processing speed (linked to hand-eye coordination), and motor coordination. There are still few studies that address this issue. However, the quality of most of the research conducted (83% intermediate or high quality) confirms the risk for neurobehavioral health in agricultural workers due to occupational exposure to pyrethroids. More research is required evaluating the exposure to pyrethroids, including biomarkers and validated neurobehavioral and neuromotor tests, in addition to evaluating the effect of simultaneous exposure to other hazardous pesticides. Assuming that the use of pyrethroids is increasing considerably and faster than the scientific evidence, it is suggested as a precautionary principle to regulate, more strictly, the sale of pyrethroids and other pesticides.

Habitual khat chewing alters urinary inorganic profile in adult healthy males

OBJECTIVES

Khat (Catha edulis) is a stimulant plant, and it is abusive to induce euphoria, alertness and activity. Concomitant use of medications and khat chewing predisposes to the appearance of drug interactions result in treatment failure or toxicity. This study determined the changes in the urinary inorganic profile in adult healthy males who are chewing khat compared with non-khat chewer males.

METHODS

A total of 40 adult non-smoker healthy males (20 khat chewer and 20 non-khat chewer) aged 24-30 years were selected. Khat chewer samples were positive for cathinone and cathine and negative for other drug of abuse, while non-khat chewer samples were negative for drug of abuse include cathinone and cathine. Samples were selected according to their results in immunoassay and gas chromatography mass spectrometry (GCMS) analysis. Cathine and cathinone were confirmed using liquid chromatography mass spectrometry (LC-MSMS) analysis. Inorganic profile includes titanium (Ti), cobalt (Co), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) were determined by using inductively coupled plasma-mass spectrometry (ICP-MS).

RESULTS

The levels of Ti, Co, Zn, Cd, and Pb in urine were significantly higher among the khat chewer group compared with non-khat chewer. Ti, Cd, Co, Pb and Zn urine levels were 0.5-, 1.5-, 1.15-, 5-, and 8.2-fold higher in the khat chewer group compared to non-khat chewer, respectively.

CONCLUSIONS

We suggested that continuous khat chewing has a long term effect on metabolic pathway of therapeutic drugs that result in toxicity or failure of therapy.

Habitual khat chewing alters urinary inorganic profile in adult healthy males

OBJECTIVES

Khat (Catha edulis) is a stimulant plant, and it is abusive to induce euphoria, alertness and activity. Concomitant use of medications and khat chewing predisposes to the appearance of drug interactions result in treatment failure or toxicity. This study determined the changes in the urinary inorganic profile in adult healthy males who are chewing khat compared with non-khat chewer males.

METHODS

A total of 40 adult non-smoker healthy males (20 khat chewer and 20 non-khat chewer) aged 24-30 years were selected. Khat chewer samples were positive for cathinone and cathine and negative for other drug of abuse, while non-khat chewer samples were negative for drug of abuse include cathinone and cathine. Samples were selected according to their results in immunoassay and gas chromatography mass spectrometry (GCMS) analysis. Cathine and cathinone were confirmed using liquid chromatography mass spectrometry (LC-MSMS) analysis. Inorganic profile includes titanium (Ti), cobalt (Co), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) were determined by using inductively coupled plasma-mass spectrometry (ICP-MS).

RESULTS

The levels of Ti, Co, Zn, Cd, and Pb in urine were significantly higher among the khat chewer group compared with non-khat chewer. Ti, Cd, Co, Pb and Zn urine levels were 0.5-, 1.5-, 1.15-, 5-, and 8.2-fold higher in the khat chewer group compared to non-khat chewer, respectively.

CONCLUSIONS

We suggested that continuous khat chewing has a long term effect on metabolic pathway of therapeutic drugs that result in toxicity or failure of therapy.

Pesticide Residue Analysis of Khat Leaves and Health Risks among Khat Chewers in the Amhara Region, Northwestern Ethiopia

Introduction

Farmers use a large number of pesticides to increase the productivity of Khat cultivation. Since Khat is consumed by many Ethiopians as a habit, there may be a significant concentration of pesticide residues in Khat leaves which result in adverse effects among the exposed population. Excess use of pesticides in Khat causes cancer, genotoxicity, and endocrine disturbances. The current study aimed to determine the concentration of selected pesticide residues on Khat leaves samples and to estimate the possible health risk on consumers.

Methods

Thirty Khat samples were collected from Khat cultivators in the Amhara region, Ethiopia. Pesticide residue extraction and cleanup of Khat samples were performed using the QuEChERS method. Data were also collected about personal variables and Khat consumption habits. The pesticide concentrations were determined and the health risks were estimated.

Results

Profenofos, dimethoate, and chlorpyrifos were detected in 6 (20%), 24 (80%), and 28 (93.3%) Khat samples, respectively. However, diazinon was detected in two samples and endosulfan I was not detected. The average concentration of chlorpyrifos, dimethoate, profenofos, and diazinon in Khat samples was 75.39 ± 20.26, 130 ± 48.94, 242.45 ± 119.79, and 81.5 ± 21.0 μg/kg, respectively. The HQ for diazinon was greater than 1 which shows the chronic health risks associated with intake of diazinon among Khat chewers. The acute health risks associated with intake of profenofos and diazinon were minimal. Discussion. Pesticide residue exposure is a risk factor for cardiac complications, reduction in antioxidant defense system, and developing neurological symptoms. All the pesticides were higher than the European Union Maximum Residue Levels (EU-MRL). Diazinon has the potential to cause higher chronic health risks. Chronic Khat chewers in the region may face potential health risks from pesticide residues. Awareness creation among people in the study area is necessary to avoid the adverse health effects of pesticide residues.

The association between awareness and behavior concerning the need for protection when using pesticide sprays and neurologic symptoms: A latent class cluster analysis

Pesticide exposure is a major health risk factor among agricultural workers, and poor protective behavior and a lack of awareness concerning the risks of pesticide use in developing countries may increase the intensity of pesticide exposure. This cross-sectional study aimed to explore the relationship between neurologic symptoms and protective behavior and awareness in relation to pesticide use in China. Latent class cluster analysis was used to categorize participants into 3 latent cluster subgroups, namely, a poor protective behavior subgroup, an excellent protective awareness and behavior subgroup, and a poor protective awareness subgroup, using a person-centered approach. Multivariate regression models were used to detect the association between the latent class cluster subgroups and self-reported neurologic symptoms. The results showed that poor protective behavior in pesticide use was an important negative predicator of neurologic symptoms such as reduced sleep quality, frequency of nightmares, debility, hypopsia, and hypomnesis. These findings suggest that targeted interventions for agricultural workers, especially local greenhouse farmers, are urgently needed to improve pesticide protection behavior.