The application of pesticides, to control pests and diseases, has spread rapidly with growing commercialisation of agriculture in Nepal. This works to some extent in the beginning; but in the long term, it brings problems like pest resistance, minor pest outbreaks and soil and water contamination. Therefore, it is necessary to understand that using pesticides is not the ultimate solution. What we need is a sustainable approach such as integrated pest management (IPM).

Since 2004, a full-fledged Pesticide Registration Office has been overseeing the appropriate use of pesticides, and plant protection officers have been appointed in each of the 75 districts who act as pesticide inspectors. The main challenge for the government is the low level of awareness among farmers about specific pesticides, their safe handling and disposal and directions for use, besides illegal marketing.

Facing repercussions

Most farmers think pesticides are medicines that cure crops from diseases, but in fact, they are toxic materials that kill or impede the growth of pests and help to increase crop yield. A wide range of pesticides are available in the market. Some of them, like persistent organic pollutants (POPs), have a comparatively high residual effect which creates health hazards. They persist for a long time in the environment and cause problems, like soil and water contamination. The major problems that are prevalent in our community can be categorised into two classes. One is a lack of awareness among farmers about the proper use of pesticides, and two, a lack of systematic marketing and monitoring systems.

According to the Plant Protection Directorate, 8,551 resellers (agrovets) have received training on the safe use and storage of pesticides. Among them, 3,493 licence holders have been selling pesticides. In Nepal, pesticides are sold not only by agrovets but also general shopkeepers. As a result, farmers are not able to get specific pesticides for specific pests and diseases, effective directions for use, and other guidance. Improper handling and storage, inappropriate transportation and unsound disposal methods are common practices that result in pesticide misuse. Similarly, illegal marketing of banned pesticides like Monocrotophos, Methyl parathion, Endosulfan DDT and Aldrin have compounded the problem.

A study carried out by the International Union for Conservation of Nature (IUCN) in 1995 showed the use of chemical pesticides at 142 gma.i./ha. The figure had leapt to 396 gma.i./ha by 2015. Pesticide use is more intensive in peri-urban areas that have greater access to markets. According to the Plant Protection Directorate, a number of food crops grown in Kavre, Dhading, Kathmandu, Chitwan, Parsa, Sindhupalchok and Bara contain excess pesticide residues and are not safe for consumption. Thus, there is an immediate need to prevent frequent, haphazard and excessive use of pesticides.

The Kalimati Fruits and Vegetables Market Development Committee is the only organisation in the country to test vegetables and other food crops for residues and maintain annual data. In 2014-15, it conducted rapid bioassay of pesticide residues (RBPR) analysis of 1,570 samples and discovered that 15 samples needed quarantine and four samples were not safe for consumption and had to be destroyed. The data for 2016-17 showed that of the 1,903 samples tested, five samples needed quarantine and 22 samples needed to be destroyed. The figures reflect the increasing incidence of high levels of pesticides.

A research report issued by the Centre for Ecogenetics and Environmental Health at the University of Washington said, “Fetuses, infants, growing children, pregnant and nursing mothers, and women of childbearing age are most at risk for adverse health outcomes from exposure to pesticides. Children are more at risk than adults because relative to their body weight, children eat more than what adults eat.” Therefore, in order to prevent health hazards, our farmers and consumers need to know about good agriculture practices and the government should focus on strengthening its extension services to the community level.

The government and researchers should concentrate on the development of resistant varieties or tolerant ones by means of gene therapy or manipulation. In the field, farmers should be encouraged to adopt integrated pest management techniques to control pest infestation and reduce the risk of crop loss.

Indigenous knowledge and practices like using ash, cattle urine and neem powder must be promoted with possible scientific manipulation to strengthen their efficacy. Using bio-pesticides and other environmental friendly means and measures of pest and disease control, and developing protective postharvest techniques that reduce or eliminate pesticide residues in food crops is another alternative. For example, washing vegetables in water for one minute at room temperature in a flume washer can reduce pesticide residues by 40-90 percent.

Similarly, washing vegetables and fruits three times under high-pressure water jets reduces residues by 60-70 percent. Agriculture produce can also be dipped in vinegar or salt for 15 minutes and then washed thoroughly. This can reduce pesticide residues by 70-80 percent. These techniques should be taught to consumers via social media. It is necessary to make farmers and consumers aware about pesticides to prevent possible health hazards.

- Kalauni is pursuing a BSc at the Agriculture and Forestry University, Nepal