The German Technical Aid Agency (GTZ)/University
of Hannover Pesticide Policy Project has pioneered important economic analysis
of the full costs of pesticide use, including examining health and environmental
costs. A new report on Thailand by Frauke Jungbluth will help the government
examine measures for policy reform.
Agriculture is a significant, though falling proportion of
the Thai economy, contributing about 11% of the gross domestic product (GDP). It
remains the main employer in the country with 64% of the total labour force. The
area planted with major crops of rice, cassava, rubber, coconut, cotton, sugar
cane and oil palm have all increased since 1970 and remained relatively stable
since 1980, although forest areas have been rapidly depleted. This reflects both
industrial expansion in the country and the falling price of agricultural
commodities relative to industrial products.
Thailand is a major market for pesticides with an annual
growth rate between 1982-92 of 8.8%, with some slowing down since then. In 1994
sales amounted to US$247 million. The herbicide market has grown rapidly in
recent years and now holds a 51% share of sales, while insecticides hold 38% and
fungicides 10%. Most pesticides are imported, and foreign companies hold the
biggest market shares: Monsanto has 15% of the market, followed by Ciba Geigy
(now Novartis), Du Pont, Cyanamid, Bayer, and Rhône Poulenc. Of imported
pesticides, 73% fall into the WHO hazard categories Ia, extremely hazardous, and
Ib, highly hazardous, and a further 33% are category II, moderately hazardous.
The three main insecticides in use are the organophosphates monocrotophos,
methamidophos, and methyl parathion, all considered particularly hazardous under
the conditions of use in developing countries. Without a major change in
government policy, pesticide imports are expected to increase in future, as more
crop land goes into the higher value fruit and vegetable production, where
pesticide use is influenced by consumer demand for uniform produce.
Health hazards
The rate of pesticide use in Thailand inevitably has
consequences for human health, though identifying the true extent of these is
difficult. Many poisoning cases are never reported and do not appear in
statistics. For example, a 1985 study concluded that only 2.4% of workers with
poisoning incidents consult a hospital. Statistics from the Ministry of Public
Health on occupational poisoning show a decrease from a high of 5,154 in 1989 to
3,165 in 1994, although there has been no change in the type and hazard of
pesticides used, or the application technology. For the first half of 1996,
1,760 people were admitted to hospital and 16 people died.
There are indications that farmers generally do not care or
are not aware of potential pesticide hazards, or if they are it does not modify
their actions in handling pesticides. About half Thai farmers apply higher than
recommended concentrations, do not pay attention to labels, wear no protective
clothing, and do not observe recommended intervals between spraying and harvest.
On the other hand, increasing numbers of farmers hire labour to spray, and wages
for spraying pesticides are about twice as high as other farm jobs.
Many of the sprayers are women, and in one survey 80% of
women reported pesticide poisoning, with acute effects including dizziness,
muscular pain, headache, nausea, weakness, and difficulty breathing. The study
estimated there could be 39,600 pesticide poisoning cases a year, with total
annual health costs of about 13 million Baht (US$507,800).
Residues are rife
Studies of pesticide residues in food conducted
between 1982-85 by the Food and Drug Administration and the Department of
Medical Science found residues in 52% of 663 samples, including DDT in 39% and
dieldrin in 15%. A 1993 survey by the National Environment Board indicated no
improvement. Pesticide residues were found in all soil samples, 86% of water
samples, 32% of fruit, 25% of vegetables and 17% of field crops. A survey of
rice in the central region in 1991-92 found residues in paddy, paddy soil and
the run off water. The pesticides analysed were monocrotophos, methyl parathion,
2,4-D and carbendazim. A study published in 1995 by the Division of Toxic
Substances found that 37% of vegetables were contaminated with organophosphorus
insecticide residues. Residues exceeding the maximum residue limits (MRLs) were
found in 20% of kale samples, 10% of cowpea, and 10% of tangerines.
Resistance
Insect resistance to pesticides has presented farmers
with a major problem, particularly in relation to the brown plant hopper (BPH)
in rice production. However heavy use of pesticides seems to have increased the
problem with BPH due to the reduction of natural enemies, with studies
ironically indicating that BPH infestation does not precede pesticide use, it
follows it. Intensified pesticide use also killed the beneficial insects which
helped control BPH. While the study found it impossible to assess all the costs
related to resistance, it could esti-mate a figure of 57 million Baht
(US$2,280,000) a year as the annual average of dealing with a major BPH outbreak
every ten years. Other costs include, for example, destruction of beneficial
insects, reduction of biodiversity, pollution of drinking water, health and
other non-agricultural consequences.
Pest resistance in vegetables has led to an overdosing of
pesticides by up to eight times the recommended rate. A recent study concluded
that vegetable growers accept that pests quickly build resistance, but sees no
alternative. Farmers are encouraged by pesticide companies to use a mixture of
products to prevent resistance build-up, and they do shift to newer products, in
spite of their much higher price. However, over time resistance still builds up,
the pesticide use creates new problems, and farmers are left in a price spiral.
Policy factors
Although there are no direct subsidies on pesticides
in Thailand, a number of factors encourage pesticide use. A favourable import
tax on pesticides has helped keep prices low. The main institute for
implementing agricultural credit policies has created opportunities for credit
to include pesticides. There is little independent information or training, and
the extension service focuses mainly on pesticide-based pest management. The
government keeps a budget for emergency outbreaks of pests, generally using
pesticides to contain the problem: for example in the case of the BPH outbreak
1989/90 which cost 250 million Baht (US$9.7 million). Investment of these funds
in on-going IPM programmes may yield better results and returns.
This study is important not only for providing key
information on the pesticide situation in Thailand, but also demonstrates the
value of a methodological framework. Other governments may be able to replicate
this approach as part of a policy of improving the infrastructure for handling
chemicals, making better investment choices, and promoting safer alternatives. (BD)
Jungbluth, Frauke, Crop Protection Policy
in Thailand: economic and political factors influencing pesticide use, Pesticide
Policy Project, GTZ/University of Hannover (fax +49 511 762 2667), Publication
Series No. 5, Hannover, December 1996, 75pp.
[This
article first appeared in Pesticides News No. 35,
March 1997, page 8]