Pesticides

Our latest annual pesticides report tells you about pesticides in the environment and what we are doing about them.

This pages make up the 2007 Pesticides report.

How do pesticides affect the environment?

Pesticides are used for controlling or destroying pests. They can be synthetic chemical or natural substances. Pesticides vary in their use, properties and potential impact on the environment.

Many pesticides are toxic to aquatic life. They can devastate rivers, lakes and groundwater if used carelessly or disposed improperly. Scientists have linked declining numbers of farmland birds over the last 50 years to pesticide use in intensive farming.

Who uses pesticides?

Agriculture and horticulture use nearly 80 per cent of all plant protection pesticides in England and Wales. Over recent years there has been some reduction in the quantity of pesticides used in agriculture and the area that they are applied over. Further information is available from the Pesticides Forum indicator report (follow the link at the bottom of the page)

Pesticides are also used to control weeds on pavements and along railway lines. The textile industry uses pesticides to stop insects attacking carpets or clothing, and timber is treated with pesticides to help it last longer.

Pesticides in rivers and groundwater

Pesticides can contaminate drinking water supplies. Groundwater contributes nearly a third of drinking water (over 70 per cent in south-east England). Polluted groundwater remains contaminated for many decades and is costly or impossible to clean up.

We report the most frequently occurring pesticides in rivers and groundwater.

Rivers In 2007 about 6.0 per cent of the indicator samples contained pesticide concentrations above the threshold of 0.1ug/l (Indicator: pesticides in rivers). This is a reduction from 2006 and is typical of levels seen over the previous years.

The most frequently found pesticides are herbicides that are mobile and persistent, and have traditionally been used in large quantities (Indicator: pesticide trends). Isoproturon is the most commonly found pesticide in rivers, followed by Mecroprop. Isoproturon is due to be take off the UK market during 2009.

Groundwater
The most frequently occurring pesticides found in groundwater in 2007 were atrazine, atrazine breakdown products and simazine (Figure 1). Atrazine substances most frequently exceed drinking water standards. The majority of groundwater sample concentrations are below the 0.1 µg/l limit.

Pesticides exceeding environmental quality standards (EQS)

Environmental Quality Standards (EQS) have been established for about 70 substances to protect the aquatic environment and organisms that live there. The distribution of EQS failures, where pesticides have been detected above specified limits, in freshwaters and tidal waters across England and Wales is shown in Figure 2.

Pesticide pollution incidents

We determine the seriousness of a pollution incident is from its impact on the environment. The effects of pollution incidents to air, land and water are categorised from 1 (the most serious incidents) to four (no environmental impact).

All pesticide pollution incidents
The number of reported category 1 and 2 incidents due to pesticides and sheep dip halved between 2005 and 2006, from 28 to 14 (Figure 3). This decrease is largely due to a drop in the number of incidents caused by sheep dip use on farms.

Plant protection pesticide incidents
Pollution incidents caused by plant protection pesticides have generally decreased in recent years. Figure 4 shows the breakdown for agricultural and non-agricultural incidents.

There was a total of eight Category 1 and 2 plant protection pesticide incidents 2007. Five of these arose from agricultural activities.

These included damage to river life following release of the herbicide trifluralin from a farm, and four incidents where water company drinking water intakes were temporarily closed because of high levels of pesticides in the intake water. In one of these the pesticide was oxadixyl, in another isoproturon, and propizamide in the other two incidents.