Overview of Levels of Organochlorine Pesticides in Surface Water and Food Items in Nigeria

Abstract

Consumption of contaminated food is one of the main routes of human exposure to pesticides. Also, surface water plays an important role in long range transport of pesticides. Persistent organic pesticides are categories under Persistent Organic Pollutants (POPs) which are organic compounds that are resistant to environmental degradation and as a result of their persistence, bioaccumulate with potential significant impacts on human health and the environment. The persistent organochlorine pesticides (OCPs) have been listed by Stockholm Convention for elimination globally. Despite the ban, some OCPs are still used illegally in developing countries. Also, from other sources, OCPs find their way into water bodies. This review therefore investigates the current levels of OCPs in surface water and food items in Nigeria and environmental/human health implications. The methodology was mainly by review of available literatures. The results were discussed in the context of criteria that designate a substance as POP, as well as in the context of allowed limit levels. Levels reported from several studies in Nigeria exceeded the water-quality criteria for surface water and maximum residue limit for food. The illegal use may be the likely sources of these pollutants in the Nigerian environment. Aquatic organisms stand the risk of acute or chronic toxicity while human health is at risk of adverse effect through consumption of contaminated food or use of polluted surface water for domestic activities. There is need for enforcement of appropriate policy to safeguard the environment and human health.

Keywords: organochlorine pesticides, persistent organic pollutants, surface water, food items