Chemical Studies on the Fate of Pesticides and Heavy Metals in the Tropical Environment

热带环境中农药和重金属归宿的化学研究

• 批准号: 63041094
• 负责人: TATSUKAWA Ryo
• 金额: $ 5.12万
• 依托单位: Ehime University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Overseas Scientific Survey.
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63041094/
• 关键词: Tropical Area; India; Developing Country; Pesticides; Organochlorine Compounds; PCB; Heavy Metals; Environmental Pollution

The continuous and large scale use of persistent and hazardous chemicals in the tropical environment are of great concern due to their global contamination and ecotoxicological impacts. In order to elucidate the behavior and fate of these chemicals such as organochlorine insecticides and heavy metals, the present research program has been undertaken in the paddy growing area of South India which has a representative tropical climate. The summary of our findings during the three year program (1987-1989) is as follows:1) Persistent organochlorine insecticides such as HCH (BHC) and DDT were detected in all the environmental media and biota with quite high concentrations. In air and water samples, these organochlorines showed higher levels from August to January, reflecting the application of insecticides largely during the flowering season of rice. The present data may aid in interpreting the role of a "Point Source" area in the global contamination of organochlorines since India is one o … More f the countries still using the persistent insecticides in large quantities.2) When the residue levels of organochlorine insecticides in air, water and paddy soil from tropical (India) and temperate (Japan) regions were compared, it was concluded that in the tropics, much larger quantities of applied chemicals were escaped rapidly into atmosphere and hydrosphere due to the high temperature and heavy rainfall and hence the continuing usage of chemicals in the tropical environment might be alarming in the context of their global contamination.3) The specific pattern of persistent orgaochlorines in tropical regions is seen not only in atmosphere and hydrosphere but also in other regimes. Analyses of human breast milk indicated the highest level of HCH and DDT in strict vegetarian group. In contrast, non-vegetarian and fishermen community showed lower concentrations. These results suggest that in India, unlike developed countries, vegetables are the principal routes of dietary exposure to organochlorine insecticides. Comparison of organochlorine levels of Indian breast milk with those of other countries revealed that HCH levels were extremely high in India and China, suggesting that they are the major point source countries of HCH pollution as of now. We also detected PCB residues for the first time in Indian breast milk, however levels were low as in other developing countries. Less

在热带环境中持续大规模使用持久性危险化学品因其全球污染和生态毒理学影响而受到高度关注。为了阐明有机氯杀虫剂和重金属等化学物质的行为和归宿，本研究项目在具有代表性热带气候的印度南部水稻种植区进行。我们在三年计划（1987-1989）期间的研究结果总结如下：1）在所有环境介质和生物群中都检测到了持久性有机氯杀虫剂，如六氯环己烷（BHC）和滴滴涕，浓度相当高。在空气和水样中，这些有机氯在八月至一月期间含量较高，反映出杀虫剂的使用主要是在水稻开花季节。目前的数据可能有助于解释“点源”区域在全球有机氯污染中的作用，因为印度是仍在大量使用持久性杀虫剂的国家之一。2) 当比较热带（印度）和温带（日本）地区空气、水和稻田土壤中有机氯杀虫剂的残留水平时，得出的结论是，在热带地区，逃逸的施用化学品数量要大得多。 由于高温和强降雨，化学物质会迅速进入大气和水圈，因此在全球污染的背景下，在热带环境中持续使用化学品可能令人震惊。3) 热带地区持久性有机氯的具体模式不仅存在于大气和水圈中，而且还存在于其他区域。对母乳的分析表明，严格素食组中六氯环己烷和滴滴涕的含量最高。相比之下，非素食和渔民社区的浓度较低。这些结果表明，与发达国家不同，在印度，蔬菜是膳食中接触有机氯杀虫剂的主要途径。印度母乳中有机氯含量与其他国家的比较显示，印度和中国的六氯环己烷含量极高，表明它们是目前六氯环己烷污染的主要点源国。我们还首次在印度母乳中检测到多氯联苯残留，但与其他发展中国家一样，含量较低。较少的