Dealing with mosquitoes is not easy, and can be very irritating. They are the cause of spreading numerous serious diseases, such as malaria, dengue, chikungunya, etc. Because of that, many of us prefer use mosquito repellents, especially incense sticks, coils, mosquito vaporiser-filled electrical
appliances, etc., to keep them away. Mosquito-repellent products are among the most commonly used items for dispelling mosquitoes during summer. A 1996 report by the World Health Organization (WHO) estimated that about 29 billion mosquito coils were used each year worldwide, and this number has continued to rise over time. Nowadays, people have adopted the idea of using mosquito repellents instead of mosquito nets while sleeping also. But while these products help prevent mosquitoes from staying in that particular region, they may also be harming our health in many ways
we don’t see. Lighting a mosquito coil or incense or mosquito vaporiser may look harmless to a normal human being, but it is more than just smoke or smell emitted from the same. When it burns, it releases a mixture of several other things:
a. Volatile Organic Compounds (VOCs), such as formaldehyde and benzene, are known to cause breathing problems and even cancer. The amount of formaldehyde released from one coil can be equal that emitted by 51 cigarettes. Other VOCs, such as methanol, carbon monoxide, toluene, xylene, and many more, are also released at the same time and can pose several health hazards.
b. Particulate Matter or tiny particles (smaller than dust) that float in the air. These can go deep into our lungs. PM2.5, a type of fine particulate matter, is released during the use of mosquito repellents and is linked to serious health issues such as heart disease, asthma, and low birth weight. The amount of PM2.5 emitted by the disc solid type was found to be higher than that from the electric liquid type. Burning just one mosquito coil can release as much fine particulate matter (PM2.5) as smoking 75 to 137 cigarettes. In fact, the indoor air pollution levels from burning one coil can be high enough to push the Air Quality Index (AQI) into the “very unhealthy” or even “hazardous” category.
c. Reactive molecules like Reactive Oxygen Species (ROS) also have severe negative effects on
health. Burning just one mosquito incense stick can release as many harmful pollutants into indoor air as a cigarette. These pollutants include toxic chemicals and tiny particles that can remain in the air long after the stick has stopped burning. Since we mostly use these repellents at night, in rooms with limited ventilation, we end up inhaling these substances for hours while we sleep. This increases the risk of long-term health effects.
The effect of these emissions on human health:
Scientists examined how these emissions from mosquito repellent affect health, especially through studies conducted on different animals like Rats, Fathead minnow, Delta smelt fish, Zebrafish, Human Corneal epithelial Cells, etc. Their findings are listed below:
- The lungs can show signs of irritation and swelling after exposure to mosquito repellent
chemicals, similar to the symptoms experienced during asthma. This can lead to coughing,
shortness of breath, and discomfort in breathing, especially in people with pre-existing respiratory conditions.
Regular exposure to these chemicals may affect the liver and kidneys, which are responsible for filtering toxins from the body. Over time, this can reduce their ability to function properly and may lead to long-term health issues. The nervous system is one of the most affected areas. Mosquito repellent chemicals are meant to paralyze insects, but at high concentrations, they can also be harmful to humans. Although primarily toxic to insects, exposure to large amounts can cause health issues in people as well.
These include breathing difficulties, skin irritation, and problems related to brain and nerve function. In humans, such exposure can disrupt normal brain activity. Breathing in, consuming, or absorbing high levels of these chemicals over a short period can result in symptoms like dizziness, headaches, nausea, tiredness, muscle spasms, confusion, seizures, or even unconsciousness. These effects are especially dangerous for children, the elderly, and individuals with conditions like asthma or heart disease. That is why it is essential to use mosquito repellents carefully and avoid prolonged exposure.
So, What Can You Do?
- Use mosquito nets while sleeping.
- Ventilate your room properly if you’re using mosquito incense, open windows to let fresh air in.
- Keep kids and elderly people away from the room while using these products.
- Avoid using mosquito repellent products that are not certified by the Central Insecticide Board or the Food and Drug Administration under any circumstances. Mosquito repellents help protect us from mosquito bites and the diseases that result from them, but they can also introduce silent threats into our homes. Scientists now know that the smoke from these products carries toxic particles and chemicals that can harm our lungs, liver, brain, and more, similar to smoking a cigarette. While we still need protection from mosquitoes, it’s time to rethink how we do it and choose safer, healthier options whenever possible.
References:
- Sudhakaran, Gokul, Dhaareeshwar VN, S. Ankit Kumar Bharti, Ashok Kumar, Jagan Kannan, and Jesu Arockiaraj. “Invisible enemies: evaluating human health threats of mosquito repellents through animal studies.” Drug and Chemical Toxicology 47, no. 6 (2024): 1341-1357.
- Wang, Lina, Xinran Zheng, Svetlana Stevanovic, Zhiyuan Xiang, Jing Liu, Huiwen Shi, Mingzhou Yu, and Chun Zhu. “Characterizing pollutant emissions from mosquito repellents incenses and implications in risk assessment of human health.” Chemosphere 191 (2018): 962-970.
- Zhu, Shengqiang, Xinran Zheng, Svetlana Stevanovic, Lin Wang, Hongli Wang, Jun Gao, Zhiyuan Xiang et al. “Investigating particles, VOCs, ROS produced from mosquito-repellent incense emissions and implications in SOA formation and human health.” Building and Environment 143 (2018): 645-651.
- Shu-Chen, Chen, Wong Ruey-Hong, Shiu Li-Jie, Chiou Ming-Chih, and Lee Huei. “Exposure to mosquito coil smoke may be a risk factor for lung cancer in Taiwan.” Journal of epidemiology 18, no. 1 (2008): 19-25.