DDE in freshwater and marine water
Toxicant default guideline values for protecting aquatic ecosystems
October 2000
Extracted from Section 8.3.7 ‘Detailed descriptions of chemicals' of the ANZECC & ARMCANZ (2000) guidelines.
The default guideline values (previously known as ‘trigger values’) and associated information in this technical brief should be used in accordance with the detailed guidance provided in the Australian and New Zealand Guidelines for Fresh and Marine Water Quality.
Description of chemical
Most organochlorine pesticides have been phased out of use in recent years, mainly because of their residual properties and potential for bioaccumulation. The guideline trigger values stated are for toxicity only and need to be adjusted for bioaccumulation where appropriate. Where the statistical distribution method was used, figures quoted are the 95% protection levels, usually applicable to slightly to moderately disturbed systems although 99% protection figures are recommended for chemicals that bioaccumulate.
DDE (CAS 72-55-9) is a persistent organochlorine insecticide, an impurity of DDT and is also a degradation product of DDT. Its chemical name is dichlorodiphenyl dichloroethylene, molecular formula is C14HCl4 and molecular weight is 310. It has very low water solubility (40 µg/L) and high log Kow of 6.06. DDE is the main metabolite of DDT and it was commonly detected in sediments and fish (Lincoln-Smith & Mann 1989, Miskiewicz & Gibbs 1994) associated with Sydney’s sewage outfalls.
Uses and environmental fate
The properties of DDE are similar to those of DDT, regarding strong adsorption to soil, bioaccumulation and persistence. Photolysis is likely to be an important process of removal of DDE from aquatic systems (HSDB 1996). Concentration factors up to 1.8x105 were determined 108 days after exposure of a pond (Callahan et al. 1979).
Aquatic toxicology
DDE has high to moderate toxicity to a range of species, at or above its water solubility. Lotufo et al. (2000) demonstrated that DDE was much less toxic to amphipods than DDT. The median lethal tissue residue levels for Hyalella azteca for DDT:DDD:DDE were in the ratio 1:24:195, but the differences were less for Diporeia sp.
Freshwater fish: 3 spp, 96-hour LC50, 32 to 240 µg/L.
Other freshwater invertebrates: 1 sp (Platyhelminthes), 96-hour LC50, 1050 to 1100 µg/L.
Marine crustaceans: 2 spp, 48 to 96-hour LC50, 2.5 to 28.0 µg/L. Chronic NOEC (14 d reproduction) for Nitrocra spinipes (harpacticoid copepod) of 0.1 µg/L.
Marine mollusc: 1 sp, 96-hour EC50, growth of 14 µg/L.
Guideline
A freshwater low reliability trigger value of 0.03 µg/L was calculated for DDE using an assessment factor (AF) of 1000. A marine low reliability trigger value of 0.0005 µg/L was calculated for DDE using an AF of 200 on the lowest of a limited set of chronic data. These figures do not account for bioaccumulation and should only be used as indicative interim working levels.
References
ANZECC & ARMCANZ 2000. Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand, Canberra.
Callahan MA, Slimak MW, Gabel NW, May IP, Fowler CF, Freed JR, Jennings P, Durfee RL, Whitmore FC, Maestri B, Mabey WR, Holt BR & Gould C 1979. Water-related environmental fate of 129 priority pollutants, Vol 1. US Environmental Protection Agency, Washington DC. EPA-440/479-029a.
HSDB (Hazardous Substances Data Bank) 1996. Micromedex Inc. 31 July 1996.
Lincoln-Smith MP & Mann RA 1989. Bioaccumulation in nearshore marine organisms. II. Organochlorine compounds in red morwong Cheilodactylus fuscus around Sydney’s three major ocean outfalls. State Pollution Control Commission, Sydney.
Lotufo GR, Landrum PF, Gedeon ML, Tigue EA and Herche LR 2000, Comparative toxicity and toxicokinetics of ddt and its major metabolites in freshwater amphipods. Environmental Toxicology and Chemistry, 19: 368–379. doi:10.1002/etc.5620190217
Miskiewicz AG & Gibbs PJ 1994. Organochlorine pesticides and hexachlorobenzene in tissues of fish and invertebrates caught near a sewage outfall. Environmental Pollution 84, 269-277.
