Impact of pesticide regulations on mortality from suicide by pesticide in China: an interrupted time series analysis

Abstract

BackgroundPesticide bans and regulatory restrictions have been shown to be effective strategies for preventing suicide in several countries. Suicide and suicide by pesticides have decreased significantly in China over the past two decades. However, whether the reduction was associated with pesticide regulation is unknown.MethodsThe monthly data on suicide and suicide by pesticide from 2006 to 2018 were obtained from China's Disease Surveillance Point (DSP) system. Information on China's pesticide regulations since 1970 was obtained from Pesticide Action Network International (PAN International), Joint Meeting on Pesticide Management Highly Hazardous Pesticides (JMPM HHP) lists, the website of the Ministry of Agriculture of China, Pesticide Information Network of China, and the Wan Fang database. Change point detection and policy analysis were combined to identify the time of any trend change breakpoint of suicide and suicide by pesticide. Interrupted time series analysis was used to investigate the pre- and post-breakpoint trends of monthly standardized rates in suicide and suicide by pesticide.ResultsThe standardized pesticide suicide rate decreased by 60.5% from 6.50 in 2006 to 2.56 per 100,000 in 2018. Larger declines were evident among people in urban areas (67.3%), female individuals (63.5%), and people aged 15–44 years (68.1%). The effect of policies banning highly hazardous organophosphorus pesticides (HHOP) [rate ratio (RR) = 0.993, 95% CIs (0.991–0.994)] in December 2008 and stopping domestic sales and use of paraquat aqueous solution (RR = 0.992, 95% CIs: 0.990–0.994) in July 2016 were more pronounced than regulating the paraquat-related products (RR = 1.003, 95% CIs: 1.002–1.004) in April 2012.ConclusionDeclines in suicide by pesticide in China occurred contemporaneously with regulatory bans and restrictions implemented on several pesticides, particularly in urban areas, among female individuals, and the relatively low age profile. These findings indicate the potential influence of these bans on trends of suicide by pesticides.

Evaluating Population-Level Interventions and Exposures for Suicide Prevention

“…We illustrate the level and slope change model using a recent study assessing the impact of pesticide regulation on suicide in China (Yan et al, 2023). Regulations to restrict access to these substances were implemented over a number of years, leading to the authors to assess the impact of three tranches of regulation.…”

Paraquat at 63 - the story of a controversial herbicide and its regulations: It is time to put people and public health first when regulating paraquat.

“…There was a decrease in suicide after the policy intervention in 2012 and a steeper decrease after the full ban of liquid formulations in 2016. The agestandardized suicide rate in China declined by 45.1% from 12.70 in 2006 to 6.98 per 100.000 in 2018 while the age-standardized pesticide suicide rate decreased by 60.5% from 6.50 to 2.56 per 100.000(77).…”