Division of Environmental Hazards and Health Effects, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA.
J Expo Sci Environ Epidemiol. 2012 Nov;22(6):569-73. doi: 10.1038/jes.2012.47. Epub 2012 Oct 10.
An outbreak of typhoid fever in rural Malawi triggered an investigation by the Malawi Ministry of Health and the Centers for Disease Control and Prevention in July 2009. During the investigation, villagers were directly consuming washed, donated, pesticide-treated wheat seed meant for planting. The objective of this study was to evaluate the potential for pesticide exposure and health risk in the outbreak community. A sample of unwashed (1430 g) and washed (759 g) wheat seed donated for planting, but which would have been directly consumed, was tested for 365 pesticides. Results were compared with each other (percentage change), the US Environmental Protection Agency's (EPA) health guidance values and estimated daily exposures were compared with their Reference dose (RfD). Unwashed and washed seed samples contained, respectively: carboxin, 244 and 57 p.p.m.; pirimiphos methyl, 8.18 and 8.56 p.p.m.; total permethrin, 3.62 and 3.27 p.p.m.; and carbaryl, 0.057 and 0.025 p.p.m.. Percentage change calculations (unwashed to washed) were as follows: carboxin, -76.6%; pirimiphos methyl, +4.6%; total permethrin, -9.7%; and carbaryl -56.1%. Only carboxin and total permethrin concentration among washed seed samples exceeded US EPA health guidance values (285 × and seven times, respectively). Adult estimated exposure scenarios (1 kg seed) exceeded the RfD for carboxin (8 × ) and pirimiphos methyl (12 × ). Adult villagers weighing 70 kg would have to consume 0.123, 0.082, 1.06, and 280 kg of washed seed daily to exceed the RfD for carboxin, pirimiphos methyl, permethrins, and carbaryl, respectively. Carboxin, pirimiphos methyl, permethrins, and carbaryl were detected in both unwashed and washed samples of seed. Carboxin, total permethrin, and carbaryl concentration were partially reduced by washing. Health risks from chronic exposure to carboxin and pirimiphos methyl in these amounts are unclear. The extent of this practice among food insecure communities receiving relief seeds and resultant health impact needs further study.
2009 年 7 月，马拉维卫生部和疾病控制与预防中心对马拉维农村地区爆发的伤寒疫情展开了调查。调查期间，村民们直接食用了已清洗、捐赠并经过农药处理的用于种植的小麦种子。本研究的目的是评估疫情社区中农药暴露和健康风险的潜在可能性。对未清洗（1430 克）和清洗（759 克）的小麦种子进行了抽样检测，这些种子原本将用于种植，但可能会被直接食用，共检测了 365 种农药。将结果相互比较（百分比变化），将美国环境保护署（EPA）的健康指导值与估计的每日摄入量与参考剂量（RfD）进行比较。未清洗和清洗后的种子样本分别含有：carboxin，244 和 57 ppm；pirimiphos methyl，8.18 和 8.56 ppm；total permethrin，3.62 和 3.27 ppm；carbaryl，0.057 和 0.025 ppm。（未清洗到清洗）的百分比变化计算结果如下：carboxin，-76.6%；pirimiphos methyl，+4.6%；total permethrin，-9.7%；carbaryl，-56.1%。只有清洗后的种子样本中的 carboxin 和 total permethrin 浓度超过了美国 EPA 的健康指导值（分别为 285 倍和 7 倍）。成人估计暴露情景（1 公斤种子）超过了 carboxin（8 倍）和 pirimiphos methyl（12 倍）的 RfD。体重为 70 公斤的成年村民每天需要食用 0.123、0.082、1.06 和 280 公斤清洗后的种子，才能超过 carboxin、pirimiphos methyl、permethrins 和 carbaryl 的 RfD。未清洗和清洗的种子样本中均检测到了 carboxin、pirimiphos methyl、permethrins 和 carbaryl。清洗后，carboxin、total permethrin 和 carbaryl 的浓度部分降低。在这种剂量下，慢性暴露于 carboxin 和 pirimiphos methyl 所带来的健康风险尚不清楚。在接受救济种子的粮食不安全社区中，这种做法的程度以及由此产生的健康影响需要进一步研究。
