Chlordane is an organochlorine insecticide historically used for agricultural purposes and as a termiticide in residential and commercial structures. Its widespread application led to its presence across various environments. Understanding its impact on human health is important, given its past prevalence and lasting environmental presence. This article explores how humans can encounter chlordane and its effects on the body.
Routes of Human Exposure
Humans can encounter chlordane through several pathways. Ingestion can occur through consuming food items like root crops grown in treated soil, or contaminated meat and dairy products from animals exposed to chlordane. Accidental ingestion of contaminated dust or soil, especially common among young children, also represents a significant pathway.
Inhalation poses another exposure risk, particularly in older homes where chlordane was used for termite control, as residues can volatilize into the air. Breathing in contaminated air near former agricultural sites or inhaling contaminated dust are also potential scenarios. Dermal absorption, or skin contact, includes touching treated surfaces, contaminated soil, or direct contact during historical application of the insecticide.
Specific Health Effects
Exposure to chlordane can lead to various adverse health effects. Neurological symptoms include headaches, dizziness, tremors, and irritability. Higher exposures can result in more severe manifestations such as convulsions and seizures.
Gastrointestinal disturbances are also associated with chlordane exposure. Individuals may experience nausea, vomiting, or diarrhea after contact, often appearing quickly following acute exposure.
The liver is another organ susceptible to chlordane’s influence. Exposure can lead to liver damage, characterized by changes in liver enzyme levels.
Chlordane has been linked to immunological effects, with studies suggesting potential immune system effects and a possible compromise to the body’s defense mechanisms.
Regarding its potential to cause cancer, chlordane is classified as a probable human carcinogen. Research has suggested an association between chlordane exposure and non-Hodgkin’s lymphoma. Animal studies have also reported liver cancer.
Reproductive and developmental effects are a concern. Animal studies suggest that prenatal and postnatal exposure may adversely affect neurobehavioral development. Skin rashes and eye irritation are additional effects that can manifest from direct contact with chlordane.
Chlordane’s Presence and Persistence
Despite its past widespread application, chlordane’s use has been significantly restricted in many countries. For instance, the U.S. Environmental Protection Agency (EPA) banned all uses of chlordane by 1988 due to concerns over cancer risk, human exposure, its buildup in body fat, environmental persistence, and danger to wildlife.
Chlordane is categorized as a persistent organic pollutant (POP), meaning it degrades extremely slowly in the environment. It can remain in soil for many years.
This persistence also contributes to its tendency to bioaccumulate, meaning it builds up in the fatty tissues of organisms over time. As it moves up the food chain, concentrations can increase significantly in higher trophic levels, leading to higher levels in top predators, including humans. Consequently, older homes or sites previously treated with chlordane can still harbor residues in the surrounding soil, indoor dust, and building materials, posing ongoing potential for exposure long after its ban.
Reducing Exposure Risks
Minimizing exposure to chlordane involves several practical steps, especially for those in older living environments. Awareness is important in homes constructed or treated before the widespread ban on chlordane, particularly concerning soil around foundations or within crawl spaces.
Effective dust control within the home is a practical way to reduce exposure, as chlordane can bind to dust particles. Regular cleaning routines, including vacuuming and wet mopping, can significantly reduce contaminated indoor dust.
Regarding food safety, thoroughly wash produce, especially root vegetables, before consumption. Growing fruit and vegetable crops in soils adjacent to foundations should be discouraged. When gardening or working in areas where chlordane might have been previously applied, wearing gloves can minimize direct skin contact with potentially contaminated soil. If significant chlordane contamination is suspected, consulting environmental professionals for testing and potential remediation is recommended.