Environmental Risk Assessment of the Chemical Lindane

Introduction
Hexachlorocyclohexane’s (HCH) are primarily used as insecticides. These pollutants have been dispersed worldwide and are extremely persistent in the environment (Walker et al. 1999). HCH’s occur in eight different isomers, one of these isomers is lindane, which is also known as gamma-hexachlorocyclohexane (Willett et al. 1998). Today most of the use of HCH is in the form of lindane, but there is great concern that this isomer can be transformed into other isomers that have a greater persistence in the environment and more harmful effects to humans and other species (Walker et al. 1999). HCH’s have a very high volatility enabling them to be transported globally, even to remote locations far away from the area of application (Walker et al. 1999; Willett et al. 1998). Lindane is the only isomer with specific insecticide properties, so since the 1950’s it started to become isolated for agricultural purposes (Vijgen et al. 2011). Lindane has been used in the past for insect control in grain, fruit, and vegetable crops. It has also been used for seed treatment (Walker et al. 1999).
Lindane is a suspected carcinogen, it is persistent, bioaccumulative, and has endocrine disrupting properties, causing lindane to become a banned substance in many countries (Vijgen et al. 2011). Lindane was also listed as a persistent organic pollutant by the Stockholm Convention in 2009 so it must be passed out and any waste or stockpiles of the chemical eliminated (Jit et al. 2011). Lindane has never been produced in Canada, an on January 1, 2005 it was de-registered for agricultural pest control uses, under the Pest Control Products Act (PCPA) (Environment Canada 2013). Lindane-based pharmaceuticals are currently produced and sold for use as a second line treatment for scabies and lice, this is under the authority of the Food and Drugs Act (FDA), but they are not widely used and there are alternatives (Environment Canada 2013; Mohebbipour et al. 2013).
Hazard Identification
Lindane is a persistent organic pollutant that was mainly used as an insecticide all over the globe. The agricultural use of lindane and the production of lindane are the main sources of environmental contamination (Vijgen et al. 2011). Lindane and other isomers of HCH can travel distances up to 22 000 km (Shen et al. 2005). Due to lindanes high volatility, it has the ability to vaporize and then condense. Lindane is found in many locations including the air, oceans, and in soil.