Something nasty in the garden shed?

The Crop Protection Association publishes annual statistics on sales to each sector of the pesticide market. A quick look at these figures shows some alarming trends in the market for home and garden pesticides. Roslyn McKendry investigates.

Selection of pesticides stored in a typical garden shed in Bedfordshire, UK. These include Roseclear, banned in June 1996, and Hexyl (containing gamma HCH [lindane]) banned in 2002. Photo: David Allen

In 2001 (the last year for which figures are available) householders purchased 4,893 tonnes of pesticide active ingredients, an increase of 14% compared with sales in 2000, and 114% compared with sales in 1997 (see table). Sales of home and garden pesticides now account for nearly 20% of the total weight of pesticides sold in the UK.
    The value of the home and garden market has risen similarly during this period – while the overall UK agrochemical market shrank by 14% between 1997 and 2001, value of sales to the home and garden sector increased by 35%. Some of this increase is due to sales of the moss-killer ferrous sulphate but there have also been significant increases in sales of insecticides.
    The arsenal of chemicals available to the amateur user is smaller than that available to professionals, and products are generally more dilute. However, unlike farmers and local authority users, amateurs have no access to training and have only label advice as a guide.
    A recent survey carried out by PAN UK indicated that over 90% of people regularly purchase chemical pesticides. Householders often use only a portion of the pesticide product they purchase and need an adequate system for disposing of the remainder. In our survey almost 60% of people reported having unwanted pesticides. Most people store these chemicals indefinitely in garden sheds while 20-30% dispose of pesticides down the drain or in the bin. Less than 10% were aware of any specialised facility for disposal of pesticide waste.
    Pesticides in drains will directly enter the water supply. Pesticides disposed of in bins may end up in landfill sites not licensed to accept hazardous waste. These landfill sites have fewer safeguards to prevent toxic chemicals leaching out and a fraction will inevitably enter and contaminate our ground and surface waters. Lawn herbicides can now be detected leaching out of most landfills in the country.

It is currently not known to what extent home and garden pesticides contribute to contamination of our environment. However, in densely populated areas, such as the Thames valley, it is highly likely that use and inappropriate disposal of home and garden pesticides contribute significantly to water contamination.
    The lack of advertised facilities for disposal of pesticides has left us with a heritage of nasty chemicals stockpiling at the bottom of the garden. Those of us who do not use chemicals ourselves may inherit the legacy from older relatives or previous home occupants. A glimpse into the average garden shed can sometimes reveal an impressive chemical armoury. In PAN UK’s survey most people reported storing pesticides, with 30-40% storing pesticides they no longer use. Some of these chemicals have long since been banned and can pose a threat to children, pets, and wildlife. Over 90% of human poisoning incidents reported to the National Poison Information Services occur at home. Pesticides ranked fourth in a Europe-wide survey of the causes of home poisoning incidents.
    European Directive 91/414 increases safety standards for pesticides used outdoors on plants. Pesticide active ingredients for which manufacturers are not intending to submit full safety testing data can no longer be legally sold after July 24th of this year. Across Europe 320 pesticide active ingredients will be coming off the market. In the UK, forty-five are coming off the market, six of which are currently licensed for amateur use; 2,3,6-TBA, dichlorprop, dikegulac, tar acids, triforine and resmethrin. These six active ingredients are present in 81 home and garden products, all of which will be withdrawn in July.
    This increase in the number of illegal pesticides will increase the problem of disposing of these chemicals. Responsibility for disposal of hazardous household waste currently lies with Local Authorities under section 51 of the 1990 Environmental Protection Act but different authorities interpret their legal responsibilities differently. Some local authorities do provide well-advertised facilities for separate collection of hazardous waste at civic amenity sites. However, the majority either have no such provision or do not advertise their facilities. Consequently obsolete and unwanted amateur pesticides are either stored indefinitely and may pose a risk, or are disposed of inappropriately, contaminating the environment. This situation calls for urgent attention.

[This article first appeared in Pesticides News No. 60, June 2003, page 11]