Japan’s pesticide regulations have been effective in reducing deaths, new analysis shows

New research has shown that Japan’s restrictions on paraquat have contributed to a 92% reduction in pesticide deaths.

Japan’s paraquat problem

Pesticide self-poisoning is a major global health problem that kills an estimated 150,000 people every year. Most deaths occur in rural communities in low-and middle-income countries, however Japan is a key exception.

Pesticide suicides reached a peak in Japan in 1985, with 2,038 recorded deaths. The herbicide paraquat was a particular problem, responsible for a significant number of deaths in the late 1970s and 1980s.

To address this, Japan introduced restrictions on the sale and use of paraquat in 1986, reducing the concentration of paraquat ion in products being sold.

A reduction in pesticide sales and deaths

The Centre for Pesticide Suicide Prevention has undertaken new research to examine the impact of Japan’s regulations on pesticide deaths.

The research team found that the dilution of paraquat products was effective in reducing herbicide and fungicide deaths by 54% over the following five years. These restrictions were also accompanied by a marked reduction in paraquat sales.

The annual number of pesticide deaths reduced significantly from 2,648 in 1986 to 221 in 2019.

In addition, while pesticide poisoning made up 8.6% of all suicides in 1985, this was down to 0.7% in 2019.

No impact on crop production

The researchers also explored the impact of the restrictions on agriculture. They analysed agricultural output across a broad range of crops, finding no apparent change.

These findings are significant as pesticide regulations often face resistance from farmers who believe that their crops will be adversely affected.

graph showing crop yields in Japan

CPSP Director Professor Michael Eddleston, who led the research, said:

“Japan is interesting as it is one of only a small number of high-income countries to have been affected by pesticide self-poisoning. We can clearly see that its restrictions on paraquat have had an impact on pesticide sales and deaths.

Although our research suggests that the dilution of paraquat may help to prevent deaths, it remains an extremely dangerous substance. In the absence of any effective antidote, there is a strong case for paraquat to be categorized as a WHO Hazard Class Ib highly hazardous pesticide.”

This study is published in Clinical Toxicology