VELLORE: Why not use waste as a green resource? This is the question that might have bothered a team of researchers led by Vice Chancellor of Thiruvallur University Dr K Murugan, before they stumbled upon a new finding. The team found that pesticides synthesised from discarded cigarette butt are highly toxic to mosquitoes which cause many infectious diseases such as malaria, dengue, etc.
The highlight of the research is that the method developed by Dr Murugan and his team is cheap and eco-friendly. The research findings were published recently in an international journal ‘Environmental Science and Pollution Research’. Dr Murugan collaborated with researchers from universities in Saudi Arabia, Italy, Taiwan and Malaysia, besides his students and faculties from Bharathiyar University in Coimbatore for developing the new method. The development of innovative mosquito control is a key prerequisite to build effective, reliable and integrated vector management strategies, he said.
‘’We found that low doses of cigarette butt extracts (with and without tobacco) showed larvicidal and pupicidal toxicity on Anopheles stephensi, the malaria causing mosquitoes, choloquine resistant parasites and microbial pathogens,’’ Dr Murugan said. According to him a single treatment of cigarette butt extracts with silver nanostructures significantly reduced egg hatchability of malaria causing mosquitoes. The methodology can be extended to control other mosquitoes that causes diseases such as dengue and so on. The path-breaking research has shown that abundant hazardous waste such as cigarette butts can be turned into an important resource for nano-synthesis of highly effective antiplasmodials and insecticides, he added.
The mosquito Anopheles stephensi is one of the most important vectors of malaria in India and other west Asian countries. Currently, the control of malaria vectors has been mainly achieved by using chemically treated nets and indoor residual spraying treatment. These methods have several drawbacks comprising development of pesticide resistant strains of mosquitoes, risks for human health and non-target organisms. The biological molecules from partially combusted materials from the butts treated with silver ions exhibited toxicity to select pathogens by the duel nature of reduction and stabilization of silver nano-particles. Smoke toxicity experiment conducted against mosquito adults using the coils made of synthesized butt extract showed reduced egg hatchability of the malaria causing mosquito. The butt extract was also found to be environmentally safe as it did not affect the bio-organisms.
‘’Our method of using cigarette butt which has nicotine, a natural plant chemical, is only targeting the mosquitoes and its larvae while sparing other organisms. Developing sprays and coils using the extract is an ideal and reliable vector management strategy,’’ Murugan said.
Murugan said that 4.5 trillion butts are discarded annually equivalent to 8.45 lakh tons of waste leading to a growing global environmental burden, this figure is expected to increase to 9 trillion by the year 2025. While we are not advocating cigarette smoking, the huge butt waste which keeps accumulating every year could be effectively converted into an eco-friendly insecticide to efficiently control malaria and other diseases, he pointed out.
Big data
International studies point out that cigarette butt amounts to 22 to 36 per cent of total litter
Even after 2 years just 38 per cent of cigarette butts decomposes
Cigarette butt extracts play detrimental effects on the fertility and longevity of mosquito offspring