Health Cost Due to Pesticide Exposure
Attributes
Medium: Health and/or Human Capital
Country: Vietnam
Analytical Framework(s): Dose-Response Approach
Unit(s): Forgone Income
Study Date: 1997
Publication Date: 1999
Major Result(s)
| Resource/Environmental Good | VND, per farmer, per hectare (1997) |
VND, per farmer, per hectare (2014)1 |
USD, per farmer, per hectare (2014)2 |
|---|---|---|---|
| Estimated health cost due to pesticide exposure as a reduction in profits per season (winter-spring) of rice production | 44,310.00 | 96,988.39 | 4.54 |
| Final health cost due to pesticide exposure as a reduction in profits per season (winter-spring) of rice production | 89,310.00 | 195,487.09 | 9.15 |
About the Inflation Adjustment: Prices in Vietnam (VND) changed by 118.89% from 1997 to 2014 (aggregated from annual CPI data), so the study values were multiplied by 2.19 to express them in 2014 prices. The study values could be expressed in any desired year (for example, to 2026) by following the same inflation calculation and being sensitive to directional (forward/backward) aggregations using your own CPI/inflation data.
Functional Transfer: Estimation involved linking the health costs of farmers with pesticide exposure through the total dose of active ingredients used by farmers, as well as with other farmer characteristics such as age, health status (weight over height ratio as proxy), and dummy variables for smoking and drinking. The following log-linear regression model was used in the estimation process, based on environmental economics literature on health production functions:
lnHC = 0.65 + 1.41 LNAGE - 0.026 HEALTH + 0.02 SMOKE + 0.72 DRINK + 0.385 LTODOSE
where lnHC is the natural logarithm of health costs of farmers; LNAGE is the natural logarithm of farmers' age (coefficient at 0.01 statistical level of significance); HEALTH is the farmers' weight over height ratio; SMOKE is the dummy for smoking (0 for nonsmoker, 1 for smokers); DRINK is the dummy for drinking alcoholic beverage(s) (0 for nondrinkers, 1 for drinkers) (coefficient at 0.01 statistical level of significance); and LTODOSE is the natural logarithm of total dosage of all pesticides used (gram a.i./ha) (coefficient at 0.01 statistical level of significance).
Study Note: Opportunity costs of medical treatment for curing poisonous symptoms (valued at VND 45,000.00, source not cited) were added to the estimated health cost to come up with the final health cost value.
Study Details
Summary: Based on a farm survey, paddy productivity and variable factors were calculated. Logit regression was then employed to relate econometrically a set of farmer characteristics to indicators of pesticide exposure to identify the types of health impairments that may be attributed to prolonged pesticide use. Afterwards, the negative effects of pesticides on the health of farmers were estimated through a dose-response function. Empirical results showed that the amount of pesticides applied (1,017 grams a.i. per hectare) was far higher than the optimal level for profit maximization (742.6 grams; loss of VND 105,644.00 per hectare). Farmers' health was influenced significantly and negatively by insecticides via the number of contacts rather than the total dose. Nonetheless, the higher the number of the doses and the number of applications of fungicides and herbicides, the larger the health cost due to exposure. A 33.4% tax on pesticide price was proposed since economic gains from input savings and decreases in health cost (VND 197,592.00) outweighed productivity losses (VND 141,416.00) having a net benefit (total benefit: returned loss in productivity) to farmers of VND 56,176.00, and government revenue (from the tax) of VND 95,833.00.
Site Characteristics: Paddy rice is the major food crop in Vietnam. However, the introduction of high-yielding varieties (HYVs) increased the use of fertilizers and pesticides to sustain yields under intensive cultivation systems. As such, in order to investigate the impacts of pesticide exposure on rice farmers' health in Mekong Delta, Vietnam, a field survey was undertaken by interviewing a random sample of 180 individual farmers from six sub-districts (selection was based on various levels of intensive paddy cultivation and pesticide application) in four provinces of the Mekong Delta.
Comments: The study comprehensively evaluated the health effects and mechanics of pesticide use in Vietnam. The methodology involved tight mathematical and statistical computations in the estimation procedure (confirmed by small sampling errors). The study also recorded farmers' acute poisoning symptoms from pesticide exposure as well as costs spent on their cure from 1992 to 1996 for purposes of comparison/verification. The transfer exercise performed from a similar study in the Philippines strengthened the integrity of the estimates.