The widely used slug and snail poison metaldehyde is turning up in rivers and in treated drinking water in the UK. In addition to its use as a molluscicide in agriculture and by home gardeners, metaldehyde is also used as a solid fuel to heat such items as banquet warming trays and small camp stoves.
Recent monitoring by the UK water industry is finding metaldehyde at levels exceeding European standards in rivers and in treated drinking water in the UK. The problem seems to be that a particularly wet late summer and fall in 2012 led to abnormally high slug populations and an enhanced use of metaldehyde by farmers.
Though the level of metaldehyde has been found exceeding the 0.1 parts per billion standard for a single pesticide in drinking water by 40 times, the UK Health Protection Agency claims that these levels pose no risk to public health or to the environment. This seems seriously at odds with the rationale for the European standard and with the seriousness with which the industry is taking the finding of these high levels of metaldehyde.
Our forecast: add metaldehyde to a growing list of substances around which the environmentally-concerned segment of the population will rally. Regulations on the use of metaldehyde will follow.
An industry-run Metaldehyde Stewardship Group, operating under the banner Get Pelletwise!, is urging extreme caution in the use of metaldehyde slug pellets. Its position statement is available at http://www.getpelletwise.co.uk/news/extreme_caution_urged_with_metaldehyde_/
An interesting perspective on the finding of metaldehyde in a British river is contained in The Guardian (UK newspaper) environment blog at http://www.theguardian.com/environment/blog/2013/jul/10/slug-pesticides-metaldehyde-drinking-water