Malaria is a life-threatening disease caused by the Plasmodium parasite, transmitted through the bites of infected Anopheles mosquitoes. Despite a significant reduction in deaths over the last 15 years, malaria remains a major global public health issue. Currently, an estimated 200 million people contract malaria each year, leading to approximately 600,000 deaths annually. The major strategies for the control of malaria include the use of insecticide-treated nets and indoor residual spraying. However, the environmental concerns associated with the use of insecticides have triggered a growing interest in environmentally friendly mosquito repellents, which offer another sustainable approach to the prevention of malaria that is free from environmental and non-target effects. This article discusses the effectiveness, advantages, and challenges of eco-friendly mosquito repellents in the prevention of malaria.
Understanding Eco-friendly Mosquito Repellents
Green insect repellents effectively repel mosquitoes without using synthetic chemicals that can harm ecosystems and human health. These eco-friendly repellents are typically made from natural ingredients and produced through sustainable practices. Here are some of the common types of green insect repellents – and how and why they work. Green repellents are also animal-friendly.
Natural Plant-Based Repellents
However, several plants naturally repel mosquitoes as they produce compounds with these traits. The culmination of these traits is the use of repellent compounds extracted from plants.
Examples:
- Citronella: (Made from lemongrass) Citronella has long been used as an essential oil in insect repellents as it overpowers the mosquitoes’ sense of smell and ruins their appetite; it is found in air fresheners, candles, sprays, and lotions.
- Eucalyptus Oil: Eucalyptus oil has eucalyptol present in it, which can repel mosquitoes very well. It can be used along with other oils.
- Neem Oil: Derived from the neem tree, neem oil repels mosquitoes and is used as an ingredient in many topical preparations.
- Pros: Plant-based repellents are easily biodegradable, humane, reasonably safe for humans and pets, and environmentally friendly in comparison with synthetic chemicals.
Biological Control Methods
Overview: Biological control involves using natural predators or microorganisms to control mosquito populations.
Examples:
- Larvivorous Fish: Larvivorous fish, such as Gambusia affinis, feed on mosquito larvae and can be used to control mosquito larvae in water.
- Bacterial Insecticides: Bacteria make insecticides like Bacillus thuringiensis israelensis (BTI) which kills mosquito larvae but is safe for other animals. Spraying BTI on water where mosquitoes breed will kill the larvae.
- Advantages: The natural approach entails minimizing environmental damage, while mosquitoes’ weakest link is attacked, reducing the overall population.
Essential Oils and Herbal Extracts
Overview: Essential oils extracted from various herbs and flowers can act as mosquito repellents.
Examples:
- Lavender Oil: Strongly appealing to us humans, this oil is highly repellent for mosquitoes. Use in diffusers or applied topically, in diluted form.
- Peppermint Oil: Peppermint oil disrupts mosquito sensory receptors that repel mosquitoes and keep them from biting.
- Pros: Naturally occurring essential oils often have the added benefit of antimicrobial properties, and will often smell better than synthetic repellents.
Benefits of Eco-friendly Mosquito Repellents
Reduced Environmental Impact
Inside-out Insect repellents have long been based on chemicals that accumulate in the environment, carrying risks of toxicity for non-target species.
Benefits:
- Biodegradability: Natural, plant-based repellents tend to degrade more quickly and are less disruptive to ecosystems.
- Safety for humans, pets, and wildlife: Eco-friendly repellents tend to be less toxic, thus lowering the risk of adverse health effects and environmental contamination.
Sustainability
Eco-friendly repellents are often from renewable sources and can be produced sustainably.
Benefits:
- Renewable Resources: Many plants provide natural repellents that we can cultivate and replant, ensuring resource sustainability.
- Local Manufacture: Local producers often create eco-friendly repellents, benefiting local economies and reducing transportation emissions.
Complementary Benefits
Overview: Many eco-friendly repellents offer additional benefits beyond mosquito protection.
Benefits:
- Aromatherapy: Components of repellents that derive from essential oils can possess calming or therapeutic properties that add value beyond insect repellency.
- Dual Purpose: Many plant-based repellents have more than one purpose, like citronella, which is used in cookery or other applications, to good effect.
Challenges and Considerations
Effectiveness
Challenge: Although natural repellents can be quite effective, they might not be as good as the synthetic alternatives.
Considerations:
- Shelf Life: Natural repellents typically have a shorter lifespan before their active ingredients break down, requiring more frequent reapplication than chemical repellents, especially in high-risk areas.
- Expert Endorsement: When a Ph.D. biologist endorses a product, it carries significant weight. However, terms like “natural” and “DEET-free” can be misleading in assessing effectiveness. While ingredients in natural repellents may come from natural sources, they can still be synthesized or combined in various proportions. Just like chemical repellents, which are safe when used as directed, some natural repellents work better than others depending on their active ingredient concentration and the specific mosquito species targeted.
Availability and Cost
Challenge: Eco-friendly repellents may be less widely available and more expensive than conventional products.
Considerations:
- Barrier/Market Penetration: Eco-friendly repellents might not be widely available, especially in low-resource settings where malaria is most prevalent.
- Cost: the high cost of natural ingredients and/or sustainable production methods might make locally sourced food cost-prohibitive for certain communities.
Integration with Other Malaria Control Measures
What is more, such eco-friendly repellents should be employed alongside other approaches to community-based malaria prevention.
Considerations:
- Combination Approaches: In combination with other methods such as insecticide-treated nets and indoor residual spraying, the use of eco-friendly repellents can improve overall malaria control efforts.
- Education and Awareness: promoting the use of eco-friendly repellents and educating communities about their benefits and limitations is essential for optimal control of malaria.
Case Studies and Examples
Community-Based Initiatives
Example: In some areas where malaria is endemic, community-based programs have added biodegradable mosquito repellents to existing malaria prevention measures. In several African countries, for example, local manufacturers of citronella candles or pure essential oil-based repellents now offer affordable and sustainable alternatives to conventional mosquito repellents.
Research and Development
For example, researchers are assessing natural repellents for their efficacy and scalability, while developing plant-based repellents and biological control agents to enhance existing malaria control tools.
As eco-friendly mosquito repellents continue to emerge, a pathway seems to be emerging towards an effective, environment-friendly solution that can tackle the problem of malaria at its source. Reducing the input of environmental-toxic molecules produced by chemical repellents, providing the ancillary benefits of natural insect repellents, and playing a role in a more integrated and environment-friendly approach to malaria control are some of the ways eco-friendly mosquito repellents help promote environmental sustainability. The effectiveness of these emerging substances in combating malaria hinges on overcoming current challenges related to effectiveness, availability, and affordability.
Eco-friendly repellents, when combined with existing malaria prevention tools and supported by educational and community-led interventions, could significantly enhance the global fight against malaria. With time and investment in research and development, we aim to provide accessible, effective, and green tools for a fight that is far from over.
