By Craig Cormick
It is no news that increased use of pesticides can lead to health problems, but a recent Philippines study has found this can in turn lead to decreased productivity.
The use of dangerous pesticides has increased globally, as there is increased pressure on farmers to grow more. In developing countries increased use and poor safety standards are often linked to chronic health problems. The currently accepted figure is that 10,000 deaths a year are caused by accidents with insecticides.
The Philippine study was conducted among rice farmers. It measured the costs of treating health problems, as well as the decreased work capacity they lead to, against productivity increases from using pesticides.
Two Filipina researchers, Flor Palis and Cynthia Marquez, working from the International Rice Research Institute, said it was one of the first studies linking medical and economic studies.
Palis said, "If you incorporate the health costs on farm productivity, the productivity of the farm is negative".
The International Rice Research Institute (IRRI) is attempting to get farmers to become less reliant on dangerous chemicals, by adopting integrated pest management techniques. These use natural controls such as predators, parasites, disease agents and weather, rather than pesticides.
Dr K.L.Heong of IRRI said that over-subsidisation of pesticides by governments was leading to their increased use.
"Pesticides are not a medicine", he said, "but are a real poison to be used only if pest monitoring shows that they are necessary".
The institute will be helped by the findings that pesticides do not lead to total productivity increases, which will help small farmers in developing countries to break their pesticide dependency.
Until recently, many high-yield crops developed by international institutions such as IRRI have been highly dependent on fertilisers and pesticides. It has been argued that such crops benefited large transnational agro-chemical companies more than small farmers.
The crops of the 1990s, however, through genetic engineering, have naturally occurring insecticides and fertilisers built into them. Such crops, together with the changed agricultural techniques, such as integrated pest management, are putting agricultural control back into the hands of small farmers.
Despite the costs, known dangers and safer alternatives, the use of pesticides in modern agriculture has grown at an alarming rate. And pesticides tend to establish a dependency, for as pests become immune to chemicals, either new pesticides have to be developed, or stronger doses must be used. As pesticides become stronger, the dangers to their handlers increase.
Between 1966 and 1987, Philippine insecticide use increased 20 times, with some farmers reporting six or more applications of pesticide a season.
The Philippines' staple crop is rice, which can be attacked by a wide variety of pests. The IRRI lists over 40 insects and worms that attack rice crops in tropical countries. For many farmers the only solution used is pesticides.
In the Philippines, the average family plot is only about one hectare, and pesticide use on that land can vary by up to eight-fold.
The researchers said that while the Philippines does formulate and repackage some pesticides, most are bought from overseas.
Theoretically, many pesticides are safe when handled properly, but in practice many farmers do not wear protective clothing, nor have special storage facilities.
Palis and Marquez also said that while the Philippines did have special occupational safety rules and regulations about handling dangerous chemicals, there was not always the infrastructure to enforce them. Problems with pesticides included the quantity of chemicals used, the number of applications made and unsafe procedures.
Many of the pesticides have been banned in developed countries. They include organophosphates such as monocrotophos, methyl parathion and chlorpyriphos and organochlorines such as endosulfan.
The researchers said that their preliminary study showed that not all farmers used safety control equipment, even when it was available, often citing cost, availability or comfort, even though they were well aware of the dangers of the chemicals.
For the most dangerous chemicals, a special respirator had to be worn, which was commonly brought from Australia and could cost up to $985.
Without such protective clothing, agricultural workers were found to be suffering many adverse effects to the eyes, skin and cardiovascular and neurological systems.
Of a sample of 56 randomly selected farmers, 41% suffered cardiac problems, 25% had low haemoglobin levels indicating anaemia, and 27% had skin problems.
Palis said a control group was located that did not use chemicals in rice farming, and it had notably fewer symptoms of ill health.
"It was very difficult to find a control group who did not use pesticides, but used natural practices", she said.
In addition to the dangers of handling pesticides, most farmers studied were also eating food contaminated by high levels of agricultural chemicals, including fish, frogs, chickens and ducks.
The researchers found widespread toxic chemicals throughout farm environments and, in one case, even in a well.
However, the Philippines, Indonesia, India and Malaysia have recently adopted integrated pest management as their official crop protection policy.
Dr Merle Shepard, of IRRI, said that the use of integrated pest management should reduce pesticide use in rice in the Philippines by 50% and save about US$10 million a year.