Pesticide use, agricultural outputs, and pesticide poisoning deaths in Japan

Abstract

Objective

Although pesticide poisonings occur worldwide, most high-income countries have not been severely affected. Japan is a key exception, with pesticide suicides becoming a major public health concern in the 1980s. We here report the epidemiology of lethal pesticide poisoning in Japan in relation to its pesticide regulation and agricultural output.

Methods

We obtained data on pesticide registration and sales from the Japan Plant Protection Association’s annual Pesticide Handbook, National Food and Agricultural Materials Inspection Center, and Food and Agriculture Organization of the United Nations. Data on deaths due to pesticide poisoning and population were obtained from Vital Statistics of Japan. We reviewed the registration status and hazard classification of pesticides in Japan and analysed the relationships between the use/sales, pesticides fatalities, and agricultural output.

Results

Five hundred and twenty-nine pesticide active ingredients are currently registered in Japan, including four WHO hazard class IB organophosphorus and carbamate insecticides. Paraquat was registered in 1962 as a liquid SL20 formulation. In 1986, restrictions were imposed on its sale/use and a 4.3% paraquat ion/4.1% diquat ion combination product registered by ICI. There were 221 pesticide poisoning fatalities in 2019, down from 2648 in 1986, a 92% reduction over 33 years. Self-poisoning was responsible for most pesticide deaths in both 1985 (2013/2476, 81.3%) and 2019 (146/221, 66.1%). Pesticide poisoning made up 8.6% of all suicides in 1985, down to 0.7% in 2019. Unintentional pesticide poisoning deaths also all fell by 83.8%, from 463 to 75. These reductions were associated with reduced sales of both OP/carbamate insecticides and paraquat/diquat but no apparent change in agricultural output across a broad range of crops.

Conclusions

Reduced use of highly hazardous pesticides and lowered concentration formulations in Japan were associated with major decreases in all deaths from pesticide poisoning and the proportion of all suicides due to pesticide ingestion.

Keywords:

• Paraquat
• diquat
• organophosphorus
• fatality
• Japan

Disclosure statement

No potential conflict of interest was reported by the author(s).

Box 1.

Pesticide registration processes in Japan.

The Agricultural Chemicals Control Law of Japan [31] was promulgated in 1948. Manufacturers apply to register their products through the Ministry of Agriculture, Forestry and Fisheries (MoAFF). MoAFF’s Pesticide Subcommittee of the Agricultural Materials Committee reviews the application form and, if no problems are identified, the pesticide is registered in Japan. These procedures are repeated three-yearly to renew the registration.

When MoAFF recognizes that a pesticide is associated with a serious problem, it suggests to the company that it suspends its manufacture and registration. Manufacturers then do not typically submit the next three-yearly application to MoAFF, although exceptions sometimes occur. For example, suspension of paraquat SL20 products was suggested in 1986 but registration of these products has continued, although sales have markedly decreased.

Additional information

Funding

The Centre for Pesticide Suicide Prevention is funded by a grant from Open Philanthropy, at the recommendation of GiveWell, USA. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising from this submission.