Uganda clings on to DDT for malaria
Sep 14, 2005
THE use of the pesticide DDT has pitted health officials against environmental activists all over the world. In Uganda, the National Environmental Management Authority (NEMA) and the Ministry of Health (MoH) are now working closely together to evaluate the possibility of reintroducing DDT use into
By Jennifer Austin
THE use of the pesticide DDT has pitted health officials against environmental activists all over the world. In Uganda, the National Environmental Management Authority (NEMA) and the Ministry of Health (MoH) are now working closely together to evaluate the possibility of reintroducing DDT use into the country’s malaria prevention programmes.
DDT has not been used in Uganda since the 1970s when international environmental activism led to bans on production and use in most countries.
DDT use and production is now governed by the Stockholm convention, an international treaty ratified in 2001 and signed by 98 countries, designed to eliminate Persistent Organic Pollutants (POPs) including DDT. Under the Convention, use of DDT is banned except in the case of a public health crisis.
The Ministry of Health recently proposed to re-introduce DDT use as a part of its malaria prevention programmes. The proposal would allow the use of DDT for internal residual spraying (IRS), a procedure in which DDT is sprayed on the inside walls of homes and buildings. The crystalline solid residue left behind serves to repel and kill mosquitoes, the vector responsible for the spread of malaria.
Environmental protection groups have demonised DDT as a threat to environmental and human health giving it a bad reputation throughout the world. However, doctors and other science experts are actively championing its use for malaria prevention in Africa. Despite all the research that has been done on the chemical (dichlorodiphenyltrichloroethane), its use in malaria prevention programmes continues to be a topic of debate.
DDT has been vilified by environmentalists, particularly in developed countries, because its excessive use as an agricultural pesticide was causing environmental damage due to its persistence, toxicity and bio-accumulativity in nature. DDT is absorbed into fatty tissue and once in the food chain becomes more concentrated in higher-level predators.
DDT does not break down quickly, and has a half-life in nature of up to 15 years. DDT was blamed in large part for the decline in bald eagles in the US and is toxic to acquatic life and reptiles.
However, DDT is also one the cheapest most effective tools in the fight against malaria in many developing countries.
Despite years of research there is very little concrete evidence on the health effects of DDT.
The US Environmental Protection Agency lists it as a ‘probable human carcinogen.’ However, Dr Roger Bate, director of the South African NGO Africa Fighting Malaria says, “After 50 years of study there is not one replicated study that shows any harm to humans at all.â€
The debate continues in circles because those on either side of the issue are talking past each other.
The large-scale use of DDT as an agricultural pesticide, and the controlled indoor use as part of a malaria prevention program are two different activities and should be assessed independently.
There is a clear rationale for the banning of DDT in agricultural settings where the environmental damages have been proven and there are affordable alternatives. However, the costs and benefits of its use in indoor spraying schemes specifically are what should be considered in evaluating its use for malaria control.
South Africa eliminated DDT from its malaria control programme in 1996. This led to one of the worst outbreaks of malaria in history of the country. According to the Malaria pdate, ‘development of insecticide resistance by Anopheles funestus mosquitoes to the synthetic pyrethroid insecticides that replaced DDT resulted in one of the most disastrous malaria epidemics in the country’s history.
Between 1996 and 2000 the number of malaria cases in South Africa increased by over 450% and malaria mortality increased by almost 1000%.’ The epidemic was not controlled until DDT was reintroduced in 2000.
Indoor spray programs use much less DDT than that used in agriculture and if applied properly, it should not leak into the environment. Indoor residual spraying uses just two grams per square metre in a contained area compared to up to a tonne of DDT per acre on a cotton field.
Given that no adverse health effects have been proven, and that DDT is a cheap effective way to combat malaria, a disease that kills over one million people per year in Africa, the MoH is moving towards reinstating its use for malaria control.
The MoH and NEMA are now working together to evaluate this proposal. “They are carrying out an EIA to see how prepared we are to undertake the activity, and to look at alternatives,†says Arnold Waiswa, NEMA Environmental Impact Coordinator.
The EIA will evaluate whether Uganda has the personnel, trained manpower, proper mitigation measures to ensure that DDT will not be illegally used for other purposes, and that it will be handled safely with proper protections for the environment and human health.
Waiswa said that the EIA would determine whether DDT use could contaminate crops and affect Uganda's agricultural exports, “The decision comes down to how prepared we are to make sure nothing leaks out.â€
By carrying out an EIA and carefully setting appropriate guidelines, Uganda should be able to ensure its agriculture and environment are protected while more effectively combating malaria, a disease leading to an estimated 1.3% decrease in GDP growth per year in Uganda.
The writer is a journalist with
The New Vision
THE use of the pesticide DDT has pitted health officials against environmental activists all over the world. In Uganda, the National Environmental Management Authority (NEMA) and the Ministry of Health (MoH) are now working closely together to evaluate the possibility of reintroducing DDT use into the country’s malaria prevention programmes.
DDT has not been used in Uganda since the 1970s when international environmental activism led to bans on production and use in most countries.
DDT use and production is now governed by the Stockholm convention, an international treaty ratified in 2001 and signed by 98 countries, designed to eliminate Persistent Organic Pollutants (POPs) including DDT. Under the Convention, use of DDT is banned except in the case of a public health crisis.
The Ministry of Health recently proposed to re-introduce DDT use as a part of its malaria prevention programmes. The proposal would allow the use of DDT for internal residual spraying (IRS), a procedure in which DDT is sprayed on the inside walls of homes and buildings. The crystalline solid residue left behind serves to repel and kill mosquitoes, the vector responsible for the spread of malaria.
Environmental protection groups have demonised DDT as a threat to environmental and human health giving it a bad reputation throughout the world. However, doctors and other science experts are actively championing its use for malaria prevention in Africa. Despite all the research that has been done on the chemical (dichlorodiphenyltrichloroethane), its use in malaria prevention programmes continues to be a topic of debate.
DDT has been vilified by environmentalists, particularly in developed countries, because its excessive use as an agricultural pesticide was causing environmental damage due to its persistence, toxicity and bio-accumulativity in nature. DDT is absorbed into fatty tissue and once in the food chain becomes more concentrated in higher-level predators.
DDT does not break down quickly, and has a half-life in nature of up to 15 years. DDT was blamed in large part for the decline in bald eagles in the US and is toxic to acquatic life and reptiles.
However, DDT is also one the cheapest most effective tools in the fight against malaria in many developing countries.
Despite years of research there is very little concrete evidence on the health effects of DDT.
The US Environmental Protection Agency lists it as a ‘probable human carcinogen.’ However, Dr Roger Bate, director of the South African NGO Africa Fighting Malaria says, “After 50 years of study there is not one replicated study that shows any harm to humans at all.â€
The debate continues in circles because those on either side of the issue are talking past each other.
The large-scale use of DDT as an agricultural pesticide, and the controlled indoor use as part of a malaria prevention program are two different activities and should be assessed independently.
There is a clear rationale for the banning of DDT in agricultural settings where the environmental damages have been proven and there are affordable alternatives. However, the costs and benefits of its use in indoor spraying schemes specifically are what should be considered in evaluating its use for malaria control.
South Africa eliminated DDT from its malaria control programme in 1996. This led to one of the worst outbreaks of malaria in history of the country. According to the Malaria pdate, ‘development of insecticide resistance by Anopheles funestus mosquitoes to the synthetic pyrethroid insecticides that replaced DDT resulted in one of the most disastrous malaria epidemics in the country’s history.
Between 1996 and 2000 the number of malaria cases in South Africa increased by over 450% and malaria mortality increased by almost 1000%.’ The epidemic was not controlled until DDT was reintroduced in 2000.
Indoor spray programs use much less DDT than that used in agriculture and if applied properly, it should not leak into the environment. Indoor residual spraying uses just two grams per square metre in a contained area compared to up to a tonne of DDT per acre on a cotton field.
Given that no adverse health effects have been proven, and that DDT is a cheap effective way to combat malaria, a disease that kills over one million people per year in Africa, the MoH is moving towards reinstating its use for malaria control.
The MoH and NEMA are now working together to evaluate this proposal. “They are carrying out an EIA to see how prepared we are to undertake the activity, and to look at alternatives,†says Arnold Waiswa, NEMA Environmental Impact Coordinator.
The EIA will evaluate whether Uganda has the personnel, trained manpower, proper mitigation measures to ensure that DDT will not be illegally used for other purposes, and that it will be handled safely with proper protections for the environment and human health.
Waiswa said that the EIA would determine whether DDT use could contaminate crops and affect Uganda's agricultural exports, “The decision comes down to how prepared we are to make sure nothing leaks out.â€
By carrying out an EIA and carefully setting appropriate guidelines, Uganda should be able to ensure its agriculture and environment are protected while more effectively combating malaria, a disease leading to an estimated 1.3% decrease in GDP growth per year in Uganda.
The writer is a journalist with
The New Vision