Suicide prevention through means restriction: impact of the 2008-2011 pesticide restrictions on suicide in Sri Lanka

OBJECTIVE:To investigate the effect of 3-year phased bans of the pesticides dimethoate and fenthion in 2008-2010, and paraquat in 2009-2011, on suicide mortality in Sri Lanka. METHODS:Age-standardised overall, sex-specific, and method-specific suicide rates were calculated using Sri Lankan police data (1989-2015). Using negative binomial regression models, we estimated the change in the rate and number of suicide deaths in post-ban years (2011-15) compared to those expected based on pre-ban trends (2001-10). FINDINGS:Overall suicide mortality dropped by 21% between 2011 and 2015, from 18.3 to 14.3 per 100,000. The decline in pesticide suicides during this same period was larger than for overall suicides: from 8.5 to 4.2 per 100,000, a 50% reduction. This was accompanied by a smaller concurrent rise in non-pesticide suicide mortality with a 2% increase (9.9 to 10.1 per 100,000). In 2015, the ratio between the observed and expected pesticide suicide rates was 0.49 (95% confidence interval [CI] 0.40, 0.62), corresponding to an estimated 937 (95% CI 574, 1389) fewer pesticide suicides than expected from pre-ban suicide rates. Findings were similar in sensitivity analyses using 2008 or 2012 as commencement of the post intervention period. CONCLUSION:Bans of paraquat, dimethoate and fenthion in Sri Lanka were associated with a reduction in pesticide suicide mortality and in overall suicide mortality despite a small rise in other methods. This study provides further evidence for the effectiveness of pesticide regulation in limiting the availability of highly hazardous pesticides and thereby reducing the number of global suicides

A marine heat wave drives massive losses from the world\u27s largest seagrass carbon stocks.

Seagrass ecosystems contain globally significant organic carbon (C) stocks. However, climate change and increasing frequency of extreme events threaten their preservation. Shark Bay, Western Australia, has the largest C stock reported for a seagrass ecosystem, containing up to 1.3% of the total C stored within the top metre of seagrass sediments worldwide. On the basis of field studies and satellite imagery, we estimate that 36% of Shark Bay’s seagrass meadows were damaged following a marine heatwave in 2010/2011. Assuming that 10 to 50% of the seagrass sediment C stock was exposed to oxic conditions after disturbance, between 2 and 9 Tg CO2 could have been released to the atmosphere during the following three years, increasing emissions from land-use change in Australia by 4–21% per annum. With heatwaves predicted to increase with further climate warming, conservation of seagrass ecosystems is essential to avoid adverse feedbacks on the climate system

Phototrophic biofilms and their potential applications

Phototrophic biofilms occur on surfaces exposed to light in a range of terrestrial and aquatic environments. Oxygenic phototrophs like diatoms, green algae, and cyanobacteria are the major primary producers that generate energy and reduce carbon dioxide, providing the system with organic substrates and oxygen. Photosynthesis fuels processes and conversions in the total biofilm community, including the metabolism of heterotrophic organisms. A matrix of polymeric substances secreted by phototrophs and heterotrophs enhances the attachment of the biofilm community. This review discusses the actual and potential applications of phototrophic biofilms in wastewater treatment, bioremediation, fish-feed production, biohydrogen production, and soil improvement