Organophosphorus pesticides (OP) are a group of phosphorus-derived organic substances frequently used in developing and underdeveloped countries to prevent and control vector-borne diseases (1). The incidence of labor origin diseases related to OP is 1.17 per 100,000 workers (2) and can cause up to 200,000 deaths per year (3). A study of neurotoxic effects associated with the use of OP, an incidence of clinical manifestations of the intermediate syndrome, is shown in between 7.7% and 84% of cases of OP poisoning (4).
The incorrect handling of the chemical has become a challenge for public and agricultural health programs because of the danger it poses from its high acute and/or chronic toxicity (5). This arises as a result of the inhibition of the enzyme acetylcholinesterase (Ach) that leads to the accumulation of acetylcholine and subsequent activation of cholinergic, muscarinic and nicotinic receptors (6).
Therefore, the central and peripheral nervous system will be persistently affected by cholinergic effects at acute exposure to low doses, which include symptoms such as nausea, headache, tachycardia, paresthesia and fasciculations (7) (8). Several articles showed that chronic exposure to OP can induce DNA damage, decreased Ach activity and hepato-nephrotoxicity, considering that this exposure causes changes in the levels of: glucose, cholesterol, triglyceride, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and Ach (9) (10) (11) (12).
Multiple epidemiological studies have identified associations between occupational exposure to OP and neurodegenerative, psychiatric and motor and sensory deficits (13) (14) (15). Prolonged exposure to low doses has been associated with anxiety crisis and depression (16).
Accordingly, in a study conducted among fruit producers in Brazil, an association was found between chronic exposure to OP and the increased prevalence of minor psychiatric and behavioral disorders (17). Then, a study of banana workers in Costa Rica concluded that there are symptoms of psychological distress and suicidal thoughts from exposure to organophosphates (18). Therefore it is hypothesized that vector control workers experience distress, presenting depressive and manic conditions because of exposure to organophosphates due to their action in the adrenergic system (19) (20). Lastly, an epidemiological report of pesticide poisoning in Ecuador, banana farmers at coastal region are highly affected by symptomatic poisoning outcomes, along with workers in the Andes and Amazon region (21).
In 1993, Leonard R. Derogatis began developing a questionnaire to assess psychological distress, which was condensed into a more concise version in 2001: the BSI − 18 (Brief Symptom Inventory) questionnaire (22) (23) (24). This 18-question survey uses the Likert scale (from 0 to 4) to evaluate three factors: somatization (items 1,4,7,10,13,16); depression (items 2,5,8,11, 14,17); and anxiety (items 3,6,9,12,15,18).
The Global Severity Index (GSI) is obtained from the sum of all the items in the questionnaire, ranging from 0 to 72. A GSI score of 13 or higher identifies positive cases of psychological distress (25). Mason (26) deemed the BSI − 18 a useful tool to assess these disorders with validity and precision (27).
The aim of this study is to identify the levels of psychological distress in personnel exposed to organophosphates (Temephos) in vector control workers according to the role they play and other characteristics in the fumigation process.