Dermal exposure of applicators to chlorpyrifos on rice farms in Ghana

Abstract

Studies evaluating dermal exposure to pesticides among applicators in tropical countries have largely been conducted using the patch dosimetry and hand wiping/washing techniques. This study used the more accurate whole-body dosimetry technique to evaluate dermal exposure to chlorpyrifos among applicators on rice farms in Ghana. The exposure levels were plotted as Cumulative Probability Distribution (CPD). Total Dermal Exposure (TDE) of chlorpyrifos among the median exposed and the 5% highly exposed groups during a spray event were 24 mg and 48 mg, respectively. When these were converted as a percentage of the quantity of active ingredient applied (Unit Exposure, UE), UE values of 0.03% and 0.06% were found among the median exposed and the 5% highly exposed groups, respectively. Overall, the hands were the most contaminated anatomical regions of the applicators, both in terms of proportion of TDE (39%) and skin loading (13 μg/cm). Also, the lower anatomical region was more contaminated (82% of TDE) compared to the upper anatomical region (18% of TDE). The levels of chlorpyrifos TDE among the applicators were found to be influenced by the quantity of insecticide applied and the height of the crops sprayed (p < 0.05). The pesticide UE data of the present study can be used to estimate the levels of dermal exposure under similar pesticide use scenarios among applicators. The findings of the present study suggest that protecting the hands and the lower anatomical regions with appropriate PPE may significantly reduce exposure among applicators.

Risk of dermal and inhalation exposure to chlorantraniliprole assessed by using whole‐body dosimetry in Korea

“…Here, when spraying onto lower crops (about 80-100 cm high), workers are exposed while moving. 20 Thus, the pesticide exposure observed within the present study (with low-lying Korean cabbage, spraying in a downward trajectory with a long wand sprayer) was robust on the legs. These results are similar to those obtained by Nuyttens et al, 21 who reported that downward spraying on tomatoes resulted in greater exposure to the upper leg, which was significantly greater than for other body parts.…”

“…However, with crops cultivated in submerged conditions, such as rice, pesticide exposure occurs often across the lower body (shins, thighs, and hips). Here, when spraying onto lower crops (about 80–100 cm high), workers are exposed while moving . Thus, the pesticide exposure observed within the present study (with low‐lying Korean cabbage, spraying in a downward trajectory with a long wand sprayer) was robust on the legs.…”

“…Overall, pesticide exposure is affected by crop type and growth rate. 20 Furthermore, when spraying downward on Korean cabbage, no significant differences in left and right bodily exposures were observed. This is consistent with results from Kim et al, 23 who measured exposure levels when spraying downward on watermelons.…”

“…reported that pesticide exposure levels on the legs when spraying peppers and beans was 62.6–63.9% of the total exposure ratio. Overall, pesticide exposure is affected by crop type and growth rate . Furthermore, when spraying downward on Korean cabbage, no significant differences in left and right bodily exposures were observed.…”

Biomonitoring of chlorpyrifos exposure and health risk assessment among applicators on rice farms in Ghana

“…Another field factor that positively correlated with the levels of ADDA was the number of spray tanks applied by the applicators (r = 0.53, p > 0.05). Some research has shown that hand contamination can be the highest contributor to total exposure among pesticide applicators (Atabila et al 2017;Baldi et al 2006;Machera 2003;Vitali et al 2009), with the most hand contamination occurring during mixing and loading of pesticides into spray tanks (Gao et al 2014;Kim et al 2014). None of the applicators in the present study used hand gloves, a situation that predisposed them to direct hand contamination.…”