Local handling of old batteries and protection from mosquito
We are carrying out a hygiene promotion project in a number of small villages (they call them camps as theoretically they are temporary) in the cacao plantages here in Ivory Coast. What we come across over and over again are loads of discarded radio batteries (the cheap big cadmium ones form Asia) as many of the inhabitants are migrant workers from the neighbouring countries.
The typically crashed old batteries are littered all around the dwellings, with the black powder emptied next to the shells. The villagers say this kills rats and mice – my concern is that it may also be harmful to the many kids around.
Have you any experience with this phenomenon? Is this practice potentially harmful – what are the symptoms and consequences of ingestion, and at what level could the stuff be dangerous for small children? How should used batteries be handled properly, especially when broken?
And while we’re at it: there is a practice of pouring some oil / diesel (?) into water storage tanks in an attempt to hamper mosquito breeding. Is this good?
I have contacted the Chartered Institute of Environmental Health and their toxicity dept to get some answers about the batteries but my contact cannot get an answer back immediately. I will also see what is possible from the usual TSS sources.
Regarding the diesel/oil on the water surface of water storage tanks, no it is not a good idea for drinking water although it would deter the mosquito from laying eggs in the water and suffocate the larvae. The preferred non toxic methods would be either to screen in the inlet of the water container or to put a 20mm layer of polystyrene beads (preferably 2mm dia) on the water surface which would act in the same way as the oil. This thickness of beads should last 4 years or more.
Polystyrene beads can be taken from broken up packaging or bought from manufacturers. They can be bought unexpanded - easier to transport and expanded by adding boiling water to them. This should only be part of a larger malaria/mosquito control programme which could include draining standing water, insecticides and bed nets and treatment of people (see Cairncross and Feachem: Environmental Health Engineering in the Tropics 2nd edn 1993 pp220 - 219
In relation to batteries the quick answer is that batteries contain heavy metals which will act as a poison. Depending on the battery constituents, this maybe short illness duration or prolonged effect. I am not a Toxicologists. The risk is soil and water supply combination is more serious.
I remember seeing an article in the Waterlines publication extolling the use of loose polystyrene beads to form a barrier layer that floats on the surface. These may be hard to obtain though and not a 'quick' solution.
The most common method to prevent mosquito breeding is to prevent access to the water using netting over vent pipes and making sure that lids and access covers are sealed. Oil barrier layers are very effective but not so healthy and must affect the taste of the water - this may be a question of 'if it is acceptable and works then leave it alone'. Probably best to ask who introduced it and ask them why this was chosen as the best way to tackle the issue.
A most effective way of reducing the incidence of malaria is through residual permethryn (treated nets, cloths, curtains, porous surfaces) in the home and on clothing. Have a scoot around on the 'net for a publication on using treated Mbu Cloths in Kenya - very effective at reducing biting and incidence of malaria in villages. An important aspect is how many people adopt measures - as in so many sanitation issues - you can protect yourself and your family but your neighbour's behaviour affects your health as well. But the mozzies in Ivory Coast are apparently resistant to all available insecticides (see the liv.ac.uk poster link below - so physical means may be the only method available to you.
The batteries are a real issue - heavy metals are cumulative (rings bells but not sure if cumulative in the soil or in organisms such as ourselves) and will contaminate the soil and the water table. If rats are eating the black powder then it is getting into the food chain that way too. Small children ferreting about in the dirt will be particularly at risk - I do not know what the immediate effects of ingestion would be though.
Sounds like you are tackling difficult-to-change behaviour issues. Influencing through education, peer pressure and through systems backed up with sanctions may be the answer. Try convincing the influential people first and ask what they would propose as measures to control the disposal of dead battery cells and reducing the mosquito population.
Even in the UK it is hard to convince people to not throw away dead battery cells into the general waste stream. The EU is imposing requirements on member states including limits on percentage of waste comprised of batteries and accumulators. Maybe a 'take-back' scheme linked to something attractive could be started? Depends if there is a market for dead batteries and on Government interest in preventing pollution and raising the standard of public health.
I google'd 'vector control ivory coast' and found a bunch of potentially useful links including https://www.lshtm.ac.uk/aboutus/people/Rowland.Mark and https://www.liv.ac.uk/media/livacuk/pgr-development/posterday/winners2013/Edi_Poster,Day,online,(1).pdf
What a tricky pair of problems you've got!
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