Organochlorine pesticides in surface sediments and suspended particulate matters from the Yangtze estuary, China

Total HCHsʹ and total DDTsʹ levels in surface sediments (SS) ranged from 0.5 to 17.5 ng g−1 and from 0.9 to 33.1 ng g−1, averaged 6.0 and 8.2 ng g−1, respectively. Total HCHsʹ and total DDTsʹ levels in suspended particulate matters (SPM) varied from 6.2 to 14.8 ng g−1 with a mean value of 12.3 ng g−1 and were from 3.4 to 25.7 ng g−1 with an average of 16.4 ng g−1, respectively. Lindane is the main HCHsʹ source and continuing use in the Yangtze Delta areas of ‘pure’ γ-HCH (lindane) rather than technical HCH (a mix of largely α- and some γ-HCH). DDTs in SS are mainly accumulated in history. However, high DDT fractions in SPM are indicators of new input of typical dicofol type DDT from 2002 to 2004. It can be seen that most samples from the Yangtze estuary were in ranges where adverse biological effects are expected, either occasionally or frequently.