Vector-borne diseases are a global problem nowadays. Mosquitoes, posing a massive threat to humans, are considered to be one of the deadliest insects that engender a high prevalence of diseases which lead to large number of morbidities. The World Health Organization (WHO), for instance, assert that 3.2 billion people are at risk of malaria, notwithstanding whether the victims are young children, pregnant women and from certain areas in the globe, specifically Africa, which have been under the mercy of this disease with 90% of the deaths caused by it. In order to prevent the rise of morbidities secondary to mosquito bites, artificial insecticides have been created; however, there are still several disputes as to the side-effects of prolonged and continuous exposure to these chemicals that post, yet, a plethora of threats to human health. Because of this, several studies on natural mosquito repellents have provided different, safe, and even more potent means to address these dangers.
The most popular form of artificial insecticide is DEET. DEET or diethyl-metatoluamide has been used since 1957 and its use has been considered safe by the American Academy of Pediatrician and the US Center for Disease Control and Prevention. However, studies have shown several side-effects due to prolonged use and exposure, as well as misuse of DEET products. The bad odour DEET repellents are known for is a trivial problem opposed to systemic damages to the human body. When exposed to the skin, 15% of the chemical are absorbed to the bloodstream allowing it to travel to the brain. This, then, supports the studies that extensive exposure to DEET causes behavioural changes and mood disorders and human brain cells are damaged causing central nervous system disorders such as seizures and insomnia. Furthermore, there are reported toxic effects on the reproductive system which generally affects the fetus causing genetic mutations.
While industrially manufactured mosquito repellents provide the necessary protection for humans, it is both boon and bane. Extrinsic means such as use of nets and screens for houses; choice of colours in clothing that are unattractive to mosquitoes; staying indoors during the times in the day when mosquitoes tend to feed; and environmental hygiene are as effective as using insecticide but cannot give as much protection that humans need. Thus studies made by scientists and chemists, even practices of quotidian people have been generating natural forms of mosquito repellents.
1. Catnip (Nepeta cataria)
Nepetalactone, the essential oil derived from catnip, was discovered and backed by studies from the Iowa State University and American Chemical Society in 2001. Its oil, when used as a mosquito repellent, is proven to have greater efficacy compared to DEET and it provides seven hours of protection.
The pure essential oil from this plant is proven safe, but unsafe when taken by mouth. Studies made by the University of Florida assert that citronella oil-based repellents can only give twenty minutes of protection at most.
3. Neem Oil (Azdirachta indica)
Also known as Neem tree or Indian lilac, this plant is grown primarily in India. It is not only used to ward of mosquitoes but also ticks. This must not be taken by mouth as it poses side effects such as lower sperm counts and abortion, and reacts to several medications.
This hackneyed household item is believed to provide protection from mosquitoes because of the pungent scent it gives of which wards off the vectors from their potential victims.
5. Lotus (Nelumbo nucifera)
For homes near lakes or has ponds, planting lotus would help in the fight against mosquitoes as they kill mosquito larvae.
6. Potent Essential Oils
The essential oils derived from lemon eucalyptus, cinnamon, castor, lavender, rosemary, lemongrass, cedar, clove, and organic soy are known to provide mosquito-repellent effects. These need to be mixed with carrier oils such as olive, sunflower, and cooking oil or they can be mixed with alcohol and vodka.
Essential oils are distasteful to mosquitoes which confuses them. Thus, oils can be utilized as repellents. In order to make one, the essential oils need to be diluted in carrier oils as specified above because they do not mix with water. As a rule of thumb, mix 5 to 10% of the oil to 10 to 20 parts of carrier oil. Apply and reapply every two hours, except for catnip-derived oils. When not in use, store the remaining oil in dark bottles and keep it away from direct heat or sunlight.
Like many products, even if it is home-made, take the necessary precautions such as checking for allergies as they may cause skin irritation. Wash the application with running water and see a physician if the rash worsens. Avoid applying the mixture in the hands of children as it must not be taken by mouth. Furthermore, repellents, both natural and artificial, are contraindicated for pregnant and lactating women.
A myriad of vector-borne diseases have caused an astronomic increase in the number of casualties. No one is exempt from this serious threat against human life. Choosing the means of protecting oneself and one’s family is completely in our hands, but we should always consider if the disadvantages would outweigh the advantages; lest our choice would lead to long-term health problems. Utilizing natural products can be as effective as the chemically-laden ones available in the market. Natural repellents are definitely safer for us and the people we love and they do not pose harmful effects to human health.