Persistence of aerially-sprayed naled in coastal sediments
Persistence of aerially-sprayed naled in coastal sediments
复制标题
DOI：
10.1016/j.scitotenv.2021.148701
复制
发表时间：
2021-07-09
影响因子：
9.8
通讯作者：
Zahran, Elsayed M.
中科院分区：
文献类型：
--
作者：
Bamiduro, Gbemisola J.;Kumar, Naresh;Zahran, Elsayed M.
2016年夏季，美国加强了对海滩地区的空中喷洒有机磷农药，以控制美国大陆本地获得的寨卡病毒爆发，人们担心海滩经常出没的地区会受到污染的沉积物。本研究的目的是评估从受影响地区获得的沉积物中naled及其副产品敌敌畏的持久性和水平。通过室内实验模拟了不同自然条件对三种沉积类型（滩砂、泥灰岩和煅烧滩砂）中nnal分解的影响。三种沉积物样品也暴露于野外空中喷洒。暴露30分钟后，沉积物中检测到的敌敌畏含量高于naled，初始施用的敌敌畏浓度为naled或敌敌畏的33 - 43%。在黑暗条件下，24小时后在沉积物上观察微量的naled水平。较高的温度加速了二氧化氯和敌敌畏在沉积物中的自然分解。在22.5℃时，naled的半衰期为3 ~ 5h，在30℃时，其半衰期为1 ~ 3h。在日光条件下，naled的分解速度加快，半衰期为20min。在野外，在空中喷洒1 h后，沉积物样品中仅检测到敌敌畏，浓度在0.0011 ~ 0.0028 μ mol/g之间。这些数据可用于风险评估，以评估通过受空中喷洒活动影响的海滩沙接触氯和敌敌畏的情况。(c) 2021 Elsevier B.V.版权所有
Aerial sprays of the organophosphate pesticide, naled, were intensified over beach areas during the summer of 2016 to control the locally-acquired Zika outbreak in the continental U.S. Concerns were raised in beach frequented areas about contaminated sediments. The aim of this study was to evaluate the persistence and levels of naled and its byproduct, dichlorvos, in sediments obtained from the affected areas. Laboratory experiments were designed to simulate the effect of various natural conditions on the decomposition of naled in three sedi-ment types (beach sand, marl, and calcinated beach sand). The three sediment samples were also exposed to field aerial sprays. After 30 min of exposure, more dichlorvos was detected in the sediments than naled, with 33 to 43% of the molar concentration initially applied as either naled or dichlorvos. Under dark conditions, trace levels of naled were observed after 24 h on sediments. Higher temperature accelerated the natural decom-position of both naled and dichlorvos in sediments. The half-life of naled ranged from 3 to 5 h at 22.5 degrees C and ranged from 1 to 3 hat 30 degrees C. Expedited decomposition of naled was observed under sunlight conditions with a half-life of naled of 20 min. In the field, only dichlorvos was detected in the sediment samples at concentrations between 0.0011 and 0.0028 mu mol/g 1 h after aerial sprays. This data can be used towards a risk assessment that evaluates exposures to naled and dichlorvos through beach sands impacted by aerial spray activities. (c) 2021 Elsevier B.V. All rights reserved.