The atlas of dialkylphosphates; assessment of cumulative human organophosphorus pesticides' exposure

Organophosphorus pesticides (OPs) are a group of chemicals with significant health interest, due to their wide spectrum of action and their excessive use both indoors (household) and outdoors (occupationally). The non-specific metabolites of OPs, dialkylphosphates (DAPs), are the most commonly used indicators for the assessment of cumulative OP exposure in humans. This review presents studies on human biomonitoring of OPs in the general population and in occupationally exposed humans. Furthermore, cases of OP intoxication determined by the measurement of DAP metabolites in various biological samples are included. In many studies, urine samples from both the general population and exposed populations have been analyzed mainly in Europe and America, while other matrices such as amniotic fluid, meconium, hair and blood have been less studied. A variety of analytical techniques were used for the determination of DAPs in these matrices. In studies measuring DAPs in urine samples, the detected concentrations ranged from 18 to 830ppb for the general population, while the corresponding values for exposed populations ranged from 29 to 1370ppb. Studies on amniotic fluid indicated DAP levels of 0.3-2.8ppb. Studies on meconium samples showed a concentration range of 0.5-16,000ppb. DAP levels in hair samples ranged from 40 to 165ppb for the general population and from 181.7 to 812.9ppb for the exposed population. Each matrix provides specific information on OP exposure, namely acute, long-term, chronic or prenatal. Meconium and hair can indicate cumulative exposure, while amniotic fluid is an indicator of fetal exposure to xenobiotics. Thus, various biological samples provide a more comprehensive view of OP exposure. In general, dimethylphosphate (DMP) and diethylphosphate (DEP) levels were higher in mainly urine samples, than other methyl and ethyl phosphates. In addition, results in the existing literature are sufficient to demonstrate the difference in levels of DAPs in general and occupationally exposed populations, mainly in urine and hair samples. However, more studies are needed to measure DAP levels in matrices such as amniotic fluid, meconium and hair to add to the literature and confirm existing data.