Lindane in freshwater and marine water
Toxicant default guideline values for protecting aquatic ecosystems
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.
Lindane is one of the isomers of g-HCH (hexachloro-cyclohexane) (CAS 58-89-9). The gamma isomer was the most insecticidally active with action by contact, ingestion and respiration. Lindane was introduced by ICI Plant Protection Ltd (Zeneca) (Tomlin 1994). Its formula is C6H6Cl6 and molecular weight is 290.8. It is only slightly soluble in water at 7.3 mg/L at 25°C (Tomlin 1994). It has a log Kow of 3.7 (Hansch et al. 1995). The current analytical practical quantitation limit (PQL) for lindane in water is 0.05 µg/L (NSW EPA 2000).
Uses and environmental fate
Lindane is an organochlorine insecticide and its uses have declined in recent years. It has been used for control of a wide range of insects and animal ectoparasites and on a range of crops (Tomlin 1994). In Australia, lindane has only two registered uses in pineapple crops (NRA 1997a). It was used in seed treatments only until 1990 (ANZEC 1991).
Lindane hydrolyses slowly, with half-lives in water between 4 and 27 days (HSDB 1996), and also biodegrades and photolyses slowly. Half-lives in river water were between 3 and 30 days and up to 300 days in a lake (HSDB 1996) and it only slowly diffuses to sediment. Lindane will bioconcentrate only slightly in fish and bioconcentration factor (BF) values between 63 and 1613 were reported (HSDB 1996).
Lindane has high to moderate toxicity, although some molluscs are less sensitive.
Freshwater fish: 27 species, 48 to 96-hour LC50, 26 to 800 µg/L, although much lower figures were reported for additional species Barbus sophore (1.5 µg/L) and Clarius batrachus (1.1 µg/L). Very high figures were reported for Barbus goriontus (7800 µg/L, additional species), Cyprinus carpio (7200 µg/L, included in above 27 species), Tilapia mossambica (4000 µg/L).
Freshwater amphibians: one species, 96-hour LC50, 3970 µg/L.
Freshwater crustaceans: 12 species, 48 to 96-hour LC50 or EC50 (immobilisation), 3.2 to 1100 µg/L. Ostracods were most sensitive. Anomalously high figures were reported for some Daphnia spp., 1790 and 3800 µg/L. Chronic no observed effect concentration (NOEC) figures were reported for Gammarus pulex (14-day growth and mortality; 2.7 to 4.3 µg/L) and for Daphnia magna (16-day reproduction; 150 µg/L).
Freshwater insects: three species, 48 to 96-hour LC50, 3.9 to 51.2 µg/L.
Freshwater molluscs: three species, 96-hour LC50, 2330 to 33,040 µg/L. The higher figures exceeded the water solubility of lindane.
Freshwater annelids: one species, 96-hour LC50, 6230 µg/L.
Freshwater rotifers: one species, chronic NOEC (mortality) of 12 to 55 µg/L.
Freshwater algae and ciliates: four species, 72 to 96-hour EC50, 1620 to 3200 µg/L. Chronic NOEC (7 to 10 day growth) of 1260 to 1270 µg/L.
Marine fish: one species, 48 to 96-hour LC50, 1.4 to 66 µg/L.
Marine crustaceans: three species, 48 to 96-hour LC50, 0.7 to 6.7 µg/L.
Marine molluscs: three species, 96-hour LC50, 18 to 26 µg/L. An additional species Mytilus galloprovincialis had outlying 96-hour LC50 figures of 4700 to 5512 µg/L.
Marine rotifer: Branchionus plicatilis 24-hour LC50 36,000 µg/L (not used).
Factors that modify toxicity
Toxicity of lindane to trout Oncorhynchus mykiss decreased by 2 to 3 times with an increase in temperature from 2°C to 18°C. In contrast, toxicity to bluegills Pimephales promelas increased by a factor of 2.6 from 7°C to 29°C. Hardness did not affect toxicity.
A freshwater moderate reliability trigger value of 0.2 µg/L was calculated for lindane using the statistical distribution method at 95% protection and an acute-to-chronic ratio (ACR) of 25.
A marine low reliability trigger value of 0.007 µg/L was calculated for lindane using an assessment factor (AF) of 100 on the lowest crustacean figure.
ANZEC 1991. Persistent organochlorine compounds in the marine environment. Australian and New Zealand Environment Council, Australian Government Publishing Service, Canberra.
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.
Hansch C, Leo A & Hoekman D 1995. Exploring QSAR. Hydrophobic, electronic, and steric constants. American Chemical Society, Washington, DC.
HSDB (Hazardous Substances Data Bank) 1996. Micromedex Inc. 31 July 1996.
NRA 1997a. Database extraction of selected pesticides: Registered uses in Australia, National Registration Authority, July 1997, Canberra.
NSW EPA 2000. Analytical Chemistry Section, Table of Trigger Values 20 March 2000, LD33/11, Lidcombe, NSW.
Tomlin C 1994. The pesticide manual: A world compendium. 10th edn, British Crop Protection Council & Royal Society of Chemistry, Bath, UK.