Sedimentary records of DDT and HCH in the Pearl River Delta, South China

Gan Zhang, Andrew Parker, Alan House, Bixian Mai, Xiangdong Li, Yuehui Kang, Zhishi Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

329 Citations (Scopus)

Abstract

Tropical regions in developing countries are thought to be significant sources of organochlorine pesticides in the global context, owing to high rate of use and only a recent production ban or restriction on application of these pesticides. In the present paper, DDT and HCH in eight 210_ Pb-dated sedimentary cores from the Pearl River Delta, South China, were analyzed in order to reconstruct the time trends of these persistent organic pollutants in this tropical region. The sedimentary inventories of ∑DDT and ∑HCH through the cores ranged from 36.6 to 1109.5 ng/cm2 and from 11.2 to 226.3 ng/cm2, respectively, and their spatial distribution implies that the water flows from the Humen, Jiaomen, Hongqili, and Hengmen outlets rather than the Xijiang flow from Modaomen outlet, supplied the major historical input of DDT to the estuary. Although a production ban of technical HCH and DDT was imposed in China in 1983, their sedimentary fluxes display increasing trends or strong, rebounds in the 1990s as recorded in the core profiles, characteristic of the increasing ratios of (DDE + DDD)/DDT and DDE/DDT. It is suggested that an enhanced land soil runoff in the process of large-scale land transform, as well as a higher river water flow in early 1990s, had mobilized these pesticides from soil to the sedimentary system in the region.
Original languageEnglish
Pages (from-to)3671-3677
Number of pages7
JournalEnvironmental Science and Technology
Volume36
Issue number17
DOIs
Publication statusPublished - 1 Sep 2002

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

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