Ever since the United States government banned the use of DDT, people have known that some pesticides can have unintended side effects in people. A new study from the University of Queensland shows that people who were exposed to the insecticide malathion had a 25% higher chance of developing chronic kidney disease.
Researchers at the University of Queensland looked at data collected from 41,847 in the U.S. National Health and Nutrition Examination Survey and found the link between kidney dysfunction and exposure to malathion.
What is Malathion?
Malathion is an insecticide that is designed to kill insects in large areas. It is the most commonly used insecticide in the United States because it has been found to be less toxic than other chemicals used to accomplish the same goal of killing insects. It is a spray that is commonly used to eradicate mosquitoes and fruit flies. It has uses in agricultural applications to prevent insects from destroying crops, including fruits and vegetables. The spray also kills insects that attack plants used in landscaping, including shrubs. It also is used in recreation areas and cities to reduce the number of mosquitos in an area.
The chemical is also used in tropical head lice treatments. Other indoor uses include use on pets to control ticks and insects, including fleas and ants.
Prior to the University of Queensland study, a direct link between adverse health impacts to humans and malathion had not been established.
Chronic kidney disease
Chronic kidney disease is also called chronic kidney failure, and it is used to describe a gradual loss of kidney function. Kidneys are the organs responsible for filtering waste and excess fluid from blood, and then flushing those out of the body through urine. People who suffer from chronic kidney disease can end up with dangerously high levels of fluid and wastes built up in the body.
The symptoms of chronic kidney disease vary depending on the severity of the damage to the kidneys. Often the symptoms are described as “non-specific,” meaning the symptoms also can be caused by other conditions or diseases. Kidneys are highly adaptable, which means they can find ways to make up for lost function. While that sounds like a positive, it actually can be a negative because a person may not develop any of these symptoms until irreversible damage to the kidneys has already happened. The symptoms of chronic kidney disease include:
- Loss of appetite
- Fatigue and weakness
- Problems sleeping
- Changes in urination frequency
- Cramping in the muscles
- Lowered mental sharpness
- Ankle and feet swelling
- Skin that is itchy and/or dry
- High blood pressure that can’t be controlled easily
- Chest pain
- Shortness of breath
Who gets chronic kidney disease?
Typically, people with chronic kidney disease are those with diabetes, high blood pressure, cardiovascular disease, or who are obese or smoke. About 1 in 10 people in high-income countries have some signs of chronic kidney disease. However, researchers see chronic kidney disease beginning to emerge in people from areas such as India, Sri Lanka, and Central America with no known cause.
It appears that spraying pesticides without wearing personal protective equipment, such as face masks and gloves, and working with soil that has been contaminated with malathion are the different ways people were exposed to the insecticide and then began to develop chronic kidney disease.
As in most studies, the data the researchers looked at had some limitations. The data from the National Health and Nutrition Examination Survey only looked at a single measurement of pesticides a person was exposed to rather than cumulative exposure over a long stretch of time. The data also did not allow researchers to pinpoint the ways that people were exposed to the insecticide.
Researchers are looking to conduct future studies that look at longer-term exposure to malathion to better understand what chronic exposure to the insecticide does to a person. They also hope to be able to determine the specific ways people are exposed to the insecticide in harmful ways. Those could include having the pesticide introduced orally through foods that have been treated with the insecticide or introduced through breathing it in while applying it or having it carried on the wind after an area was treated.
Written by Sheena McFarland