Pesticides in Our Homes: Malathion’s Health Effects


Home / Pesticides in Our Homes: Malathion’s Health Effects
Malathion is used to treat pests like the mosquito. Image by: USDA

We use malathion to kill pests like the mosquito. Image by: USDA

Mosquitoes, lice, and bedbugs – they’re common parasites everyone loves to hate.

We spray them, bug bomb them, and comb chemicals through our kids’ hair to get rid of infestations. But what are all those chemicals doing to us? Are they hurting our kids?

Lets take a look at one common pesticide; malathion.

Malathion: Organophosphate

Malathion is part of a group called organophosphates. Organophosphates are some of the most common and most toxic insecticides used today, according to the Pesticide Action Network.

Organophosphates are similar to chemical warfare agents that we used during WWII – even at low levels, organophosphates can affect the human nervous system.

Malathion is an insecticide that we use to control a wide variety of pests in the agricultural world and around people’s homes – in mosquito and bedbug control as well as in some lice treatments. Decoded Science’s John Jaksich, chemist, states,

“The specific problem with malathion is this: It is an organo-phosphate but possesses lower toxicity threshold than other organophosphates. In other words, it takes more of this chemical to be harmful, but you may find it in higher overall concentrations.”

Exposure to Malathion

You can be exposed to malathion by getting it on your skin, or breathing it in. If you handle a product with malathion and don’t wash your hands before you eat, you can ingest it as well. You can also be exposed to malathion if you eat treated produce.

Malathion Poisoning

According to Oregon State University’s National Pesticide Information Center, people who are exposed to a high enough level of malathion can experience nausea, vomiting, muscle tremors, cramps, weakness, abdominal pain, and diarrhea. When malathion enters your body, it travels to your liver and kidneys and affects your nervous system. Children may experience different symptoms including, fatigue, seizures, constricted pupils, excessive salivation, muscle weakness, and coma.

Malathion can be dangerous to your health in large enough doses. Image by Benjah-bmm27

Malathion can be dangerous to your health in large enough doses. Image by Benjah-bmm27

Malathion vs. Malaoxon

Jaksich further explains, “Why are organo-phosphate compounds toxic? Once the malathion compound passes into the bloodstream, the liver (utilizing Cytochrome P450) attempts to break down the compound to a non-toxic form. The result, unfortunately, is a more toxic form of the compound—Malaoxon. It is Malaoxon that finds its way to the ‘nerve-endings’ of peripheral nervous system, which can cause paralysis and possibly convulsions.”

Malaoxon: Reference Dose

A reference dose is an estimate of the quantity of a chemical that a person could be exposed to everyday for the rest of their life without adverse health effects. The U.S. EPA has established an acute reference dose of 0.14mg/kg/day for the general population. NIOSH has also set the level of malathion in the air that is immediately dangerous to life and health (IDLH) to be set at 250mg/m3.

Toxicity Adjustment for Malaoxon

Malaoxon is 61 times more toxic than malathion, reports the Environmental Protection Agency (EPA). The EPA characterizes the level of toxicity in terms of its degree of potency compared to the parent compound; in this case malathion. The ratio of the relative toxicity between the parent (malathion) and the oxon (malaoxen) is called Toxicity Adjustment Factor (TAF). The EPA states,

… in the absence of an acute TAF, the chronic TAF of 61x calculated from oral studies is applicable to residues of malaoxon for risk assessment of all exposure duration, routes, and scenarios and is considered to be health protective.”

Malathion, Malaoxon, and You

Malathion maybe more prevalent in our lives than we may think; from lice treatment to pesticides, this organophospahte is common in and around homes. This chemical can be dangerous in large enough doses and can cause unpleasant and dangerous side effects, but that’s not all. Malaxon, the result of malathion breaking down, is 61 times stronger than malathion.

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