Aldrin and Dieldrin

Introduction
Effects on Humans
Effects on the Aquatic Environment
Monitoring Techniques and Standards
Safety Cards
Links

Introduction

*IARC: International Agency for Research on Cancer

Aldrin and dieldrin are common names for two closely related chemicals that have been widely used for controlling soil insects and certain insect vectors of disease. Aldrin, which readily breaks down to dieldrin in living systems, is used to control soil pests (namely termites) on corn and potato crops. Dieldrin is also an insecticide used on fruit, soil and seed, and has been used to control tsetse flies and other vectors of tropical diseases. Because the chemicals are intended for use on insects in soil. Aldrin and dieldrin readily bind to sediment and are rarely leached to groundwater. Dieldrin, for example, persists in soils with a half-life of five years (WFPHA, 2000) at temperate latitudes, while it disappeared up to 90% in one month in tropical areas. (WHO, 1989). Both may be volatilised from sediment and redistributed by air currents, contaminating areas far from their sources. (WFPHA, World Federation of Public Health Associations, 2000). Another route of transfer appears to be surface run off. (WHO, 1989).

Aldrin and dieldrin have been banned in most developed countries but, aldrin is still used as termiticide in some others. However, aldrin and dieldrin have also been identified in organisms in Arctic waters and in sediments in the Great Lakes basin, suggesting long range transport from southern agricultural regions. (WFPHA, 2000).

In a study of breast-fed infants in Australia, 88 percent of the offspring were found to exceed the World Health Organization's Acceptable Daily Intake (ADI) allowance (0.0001 mg/kg bw combined total aldrin+dieldrin, 1994). Dieldrin has been isolated in the amniotic fluid in tissues of developing human foetuses, confirming its capacity for placental transfer. The half-life of the residues in humans is approximately nine to twelve months, and the rates of excretion of dieldrin are roughly equal to the average daily intake for most people. (WFPHA, 2000).

Effects on Humans

Acute exposure in humans causes adverse effects, between these, are headache, irritability, dizziness, loss of appetite, nausea, muscle twitching, convulsions, loss of consciousness, and possible death. These conditions may persist for a few weeks following exposure, but have not been shown to be permanent. The lethal dose of aldrin for an adult male is estimated to about 5 grams. Dieldrin is 40 to 50 times more toxic than DDT. (WFPHA, 2000).

Effects on the Aquatic Environment

Aldrin and dieldrin produce adverse enzymatic and hormonal change in fish that lead to impaired reproductive ability. Aldrin bioconcentrates in molluscs and fish, and high levels of dieldrin have been found concentrated in fish, sculpins, snails, and lake trout. (WFPHA, 2000).
The table below shows some bioaccumulation factors for dieldrin (EHC 91, WHO, 1989).

Monitoring Techniques and Standards

The HSDB, Hazardous Substances Data Bank: type Aldrin and Dieldrin

This site reports a full list of information on the substance as: Human Health Effects, Animal Toxicity Studies, Environmental Fate & Exposure, Environmental Standards & Regulations, Chemical/Physical Properties, Chemical Safety & Handling, Occupational Exposure Standards, Laboratory Methods, Synonyms and Identifiers.

Toxicology report with toxicity data from the Vermont Safety Information Resources, Inc.

This site provides a list or toxicity tests results, references for toxicity literature reviews, USA standards and regulations, occupational exposure limits in different states all over the world, and reference to NIHOSH, National Institute for Occupational Safety and Health, analytical standard methods.

Safety Cards

ICSC, International Chemical Safety Cards European Union version

The International Occupational Safety and Health Information Centre (CIS) access to International Chemical Safety Cards: two pages data sheets on pure substances from the ILO/WHO/UNEP International Program on Chemical Safety (IPCS).

ICSC, International Chemical Safety Cards U.S. National version

The National Institute for Occupational Safety and Health (NIOSH) access to
International Chemical Safety Cards.

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