Lindane and Technical HCH Residues in Indian Soils and Sediments: A Critical Appraisal

Even at low residue concentrations, persistent organic pollutants (POPs) are of increasing concern all over the world. They include numerous organochlorine pesticides, like hexachlorocyclohexane (HCH), known for its toxicity, lipophilic properties and very long turnover time. To test and settle the appropriate prevention and remediation measures, there is an imperative need to delineate suspected contaminated areas and to acquire information regarding the historical and actual production, usage and storage; the probable fate and the contamination situation of these compounds in the environment.

India is a major producer and, although it officially banned HCH in 1990 for agricultural purposes, it is still permitted for the health protection programme (vector-transmitted diseases). The present report aims to address the actual contamination of soils and sediments in India with technical HCH and lindane for the period 1996-2003.

The assessment was conducted using different sources of data: beside specialized scientific databases, general search engines were used. Information was also sought by visiting websites and sending a request letter to authors of publications, in charge of NonGovernmental Organizations, international organizations, companies and Indian governmental and research institutions.

The appraisal revealed that, on a national level, there is a lack of information regarding lindane residues in soils and sediments. The description of parameters influencing residual concentrations of these compounds in soils is frequently omitted in these reports and the few investigations conducted do not cover the whole country, dismissing the Eastern and Central States. However, such a situation is not unique to India, and the information appears to be also scarce and patchy for many developing and developed countries worldwide.

In our opinion a harmonized sampling procedure should be agreed upon at a national level and a standard procedure for lindane measurement be set at an international level. This will allow for making comparisons between different countries and improve our understanding of lindane behaviour in soil and its management. To achieve this we need enough data and obviously data of good quality, but not only this. Geographic Information System would be a very valuable tool to gather all the available information and to assess residues of HCH and other POPs at a local, regional, national and international level.