Impact of paraquat regulation on suicide in South Korea.

BACKGROUND: Ingestion of pesticides (mainly paraquat) accounted for one-fifth of suicides in South Korea in 2006-10. We investigated the effect on suicide mortality of regulatory action, culminating in a ban on paraquat in South Korea in 2011-12. METHODS: We calculated age-standardized method-specific suicide mortality rates among people aged ≥15 in South Korea (1983-2013) using registered death data. Negative binomial regression was used to estimate changes in the rate and number of pesticide suicides in 2013, compared with those expected based on previous trends (2003-11). RESULTS: Pesticide suicide mortality halved from 5.26 to 2.67 per 100 000 population between 2011 and 2013. Compared with the number expected based on previous trends, the regulations were followed by an estimated 847 [95% confidence interval (CI) -1180 to -533] fewer pesticide suicides, a 37% reduction in rates (rate ratio = 0.63, 95% CI 0.55 to 0.73) in 2013. The decline in pesticide suicides after the regulations was seen in all age/sex/geographical groups. The absolute reduction in the number of suicides was greatest among men, the elderly and in rural areas. The reduction in pesticide suicides contributed to 56% of the decline in overall suicides that occurred between 2011 and 2013. There was no impact of the regulations on crop yield. CONCLUSIONS: The regulation of paraquat in South Korea in 2011-12 was associated with a reduction in pesticide suicide. Further legislative interventions to prevent the easy availability of highly lethal suicide methods are recommended for reducing the number of suicides worldwide.

Changes in chlorophyll a fluorescence of glyphosate-tolerant soybean plants induced by glyphosate: in vivo analysis by laser-induced fluorescence spectroscopy.

A significant increase in the use of the herbicide glyphosate has generated many questions about its residual accumulation in the environment and possible damage to crops. In this study, changes in chlorophyll a (chl-a) fluorescence induced by glyphosate in three varieties of glyphosate-resistant soybean plants were determined with an in vivo analysis based on a portable laser-induced fluorescence system. Strong suppression of chl-a fluorescence was observed for all plants treated with the herbicide. Moreover, the ratio of the emission bands in the red and far-red regions (685 nm/735 nm) indicates that the application of glyphosate led to chlorophyll degradation. The results also indicated that the use of glyphosate, even at concentrations recommended by the manufacturer, suppressed chl-a fluorescence. In summary, this study shows that fluorescence spectroscopy can detect, in vivo, very early changes in the photosynthetic status of transgenic soybeans treated with this herbicide.

Mortality, length of life, and physical examination attendance in participants of the Air Force Health Study.

Begun in 1982, the Air Force Health Study (AFHS) has assessed the mortality of veterans of Operation Ranch Hand, the unit responsible for aerially spraying herbicides in Vietnam. A comparison group of other Air Force veterans involved with aircraft missions in Southeast Asia during the same period, but not involved with spraying herbicides, was included in the study. Among 18,082 veterans, this report examined whether attendance at AFHS physical examinations from 1982 to 1999 played a role in mortality experience and potential lengthening of life relative to veterans who did not attend. The years of potential life lost for 1173 veterans who died before age 65 was calculated. No statistically significant difference in risk of death was found from all causes, cancer, or circulatory disease between attendees and nonattendees. No evidence was found to suggest that attending physical examinations decreased mortality or substantially lengthened life in AFHS participants.