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Information - This Indicator is an experimental statistic and has been published in order to facilitate user involvement in its development – information on how the data have been obtained and how the indicator has been prepared is available via the link(s) in the 'Readiness and links to data' section. We would welcome any feedback, particularly on the usefulness and value of this statistic, via 25YEPindicators@defra.gov.uk.

H4: Exposure and adverse effects of chemicals on wildlife in the environment

Short Description

This indicator tracks changes in the exposure of wildlife to chemicals in the environment over time and considers the potential risks to wildlife from chemicals in terrestrial, freshwater and marine ecosystems. Data are currently available for representative chemicals in surface waters and in certain species of birds of prey, fish, mammals, and mussels. Other relevant exposure data will be incorporated in the future. Further work is ongoing to improve reporting for exposure metrics and to understand better the effects of chemicals on wildlife populations and individuals.

This indicator is complementary to other indicators within the framework that give data on environmental pressures from chemicals, for example, ‘B1 Pollution loads entering waters’ and ‘H3 Emissions of mercury and persistent organic pollutants to the environment’.

Readiness and links to data

This indicator is not available for reporting in 2023 in a finalised form. The interim indicator presented here is consistent with that published in 2021 as an experimental statistic. It covers the exposure of wildlife to chemicals in the environment and, where feasible, the potential risk from different types of chemicals to wildlife on land and in water. The indicator is based on chemical concentrations found in surface waters and in different organisms – sparrowhawk/red kite, red fox (data extraction under development), freshwater fish, otter, blue mussel, dab, and harbour porpoise. It covers 3 environmental compartments: terrestrial, freshwater and marine (estuarine, coastal and offshore).

The chemicals are representative of 3 groups highlighted for attention under the 25 Year Environment Plan: (1) persistent, bioaccumulative – the accumulation of a substance over time in a living organism – and toxic (PBT) substances, (2) heavy metals, and (3) pesticides and biocides. There are no new assessments to report in 2023, but we aim to update the indicator in 2024 as further data become available.

These data are being published as an experimental statistic to facilitate user involvement in the development of this indicator.

We would therefore welcome any feedback on these statistics, particularly on their usefulness and value, via 25YEPindicators@defra.gov.uk.

Further details on the data analysis used for the presented indicator are given in the supporting H4 indicator report. Some data relevant to this indicator are published on the following data platforms: Predatory Bird Monitoring Scheme – contaminant exposure, Water Quality Data Archive, Water quality monitoring gas chromatography–mass spectrometry and liquid chromatography–mass spectrometry semi-quantitative screening data, British Oceanographic Data Centre - Monitoring and Assessment National Database (MERMAN).

Since the publication of the H4 indicator report in 2021, we have been working to improve our understanding of exposure of wildlife to the chemical contaminants presented, including by analysis of archived samples to address data gaps and get a picture across environmental compartments. This will enhance our ability to report exposure trends.

We use readily available data where possible. Because legislative drivers for the environmental monitoring of chemicals producing such data have historically focussed on freshwater and marine environments, we are looking at the best ways to monitor for chemicals to build a baseline for the terrestrial environment.

We are exploring methods for assessing chemical contaminant effects on wildlife to improve our understanding of environmental impacts and the potential to report these under the indicator.

In addition, we are initiating the development of metrics for emerging chemical risks. This includes integrating results from the Prioritisation and Early Warning System (PEWS) for chemicals of emerging concern, which was developed in response to the 25 Year Environment Plan to consolidate work on monitoring and horizon scanning. PEWS includes consideration of the risks posed by emerging contaminants to surface and groundwaters, biota, soils, and sediments. The approach taken on emerging risks will also seek to incorporate the consideration of broader chemical topics which extend beyond PEWS. As our understanding of these emerging risks develops further, work is required to determine the potential for incorporating them into H4 indicator reporting or elsewhere.

Notes on indicator

Available thresholds for wildlife have been used to provide context to the most-recent national concentrations and these are given in the supporting report to this indicator. They are not statutory values within the indicator. Their use to indicate risk does not represent a compliance assessment and should not be compared with other regulatory reporting regimes which may use values with different protection goals. The approach for selecting thresholds is specific to the wildlife or environmental medium being considered because of the data available and the purpose for which it was gathered. Monitoring networks, analytical methods and thresholds can change over time.

The freshwater assessment for pesticides is currently based on a threshold for short-term toxic effects. In the future, the approach will be adapted to reflect risks from chronic exposure.

Additional data are available for otter, freshwater fish and red fox which cannot be incorporated into the dashboard at present, but are provided in the supporting report. The report also contains information on spatial variation in results for freshwater metals sites and for marine fish.

Indicator components

Table H4: Exposure of wildlife to chemicals in the environment in England and, for some marine components the UK; up to 2019 where available

Chemical Blue mussels Dab Estuarine/coastal waters Freshwater Harbour porpoise Otter Red fox Roach/chub/brown trout Sparrowhawk/red kite
Cadmium No observed changes in concentrations. No threshold available. No observed changes in concentrations. No threshold available. No observed change in concentrations. All sites average below threshold. No observed change in concentrations. 1 to 24% sites above threshold. Insufficient data or no comparable data available. No observed changes in concentrations. No threshold available. Insufficient data or no comparable data available. Insufficient data or no comparable data available. No observed change in concentrations. All individuals average below threshold.
Copper No observed changes in concentrations. No threshold available. No observed changes in concentrations. No threshold available. No observed change in concentrations. All sites average below threshold. No observed change in concentrations. 1 to 24% sites above threshold. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data or no comparable data available. No observed changes in concentrations. No threshold available.
Lead No observed changes in concentrations. No threshold available. No observed changes in concentrations. No threshold available. No observed change in concentrations. All sites average below threshold. No observed change in concentrations. 1 to 24% sites above threshold. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data or no comparable data available. No observed change in concentrations. All individuals average below threshold.
Mercury No observed change in concentrations. More than 75% sites above threshold. No observed change in concentrations. More than 75% samples above threshold. Not relevant - unlikely to be an exposure route. Not relevant - unlikely to be an exposure route. Insufficient data or no comparable data available. No observed change in concentrations. Population average below threshold. Insufficient data or no comparable data available. No observed change in concentrations. More than 75% sites above threshold. No observed change in concentrations. Population average below threshold.
Nickel No observed changes in concentrations. No threshold available. Increasing concentrations. No threshold available. No observed change in concentrations. 1 to 24% sites samples above threshold. No observed change in concentrations. 1 to 24% sites above threshold. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Decreasing concentrations. No threshold available.
PBDEs Insufficient data for trend assessment. All sites below threshold. Decreasing concentrations. 1 to 24% samples above threshold. Not relevant - unlikely to be an exposure route. Not relevant - unlikely to be an exposure route. Decreasing concentrations. All individuals below threshold. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data for trend assessment. All sites below threshold. Insufficient data or no comparable data available.
PCBs Insufficient data for trend assessment. 50 to 74% sites above threshold. Decreasing concentrations. 25 to 49% samples above threshold. Not relevant - unlikely to be an exposure route. Not relevant - unlikely to be an exposure route. No observed change in concentrations. 50 to 74% individuals above threshold. Insufficient data or no comparable data available. Insufficient data or no comparable data available. No observed change in concentrations. No threshold available. Insufficient data or no comparable data available.
PFOS Not relevant - unlikely to be an exposure route. Insufficient data for trend assessment. All samples below threshold. Insufficient data or no comparable data available. Insufficient data for trend assessment. 1 to 24% sites above threshold. Decreasing concentrations. All individuals below threshold. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data for trend assessment. 1 to 24% sites above threshold. Insufficient data or no comparable data available.
Pesticides Not relevant - unlikely to be an exposure route. Not relevant - unlikely to be an exposure route. Not relevant - unlikely to be an exposure route. Insufficient data for trend assessment. 1 to 24% sites samples above threshold. Not relevant - unlikely to be an exposure route. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data or no comparable data available.
SGARs Not relevant - unlikely to be an exposure route. Not relevant - unlikely to be an exposure route. Not relevant - unlikely to be an exposure route. Insufficient data or no comparable data available. Not relevant - unlikely to be an exposure route. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data for trend assessment. 1 to 24% samples above threshold.
Zinc No observed changes in concentrations. No threshold available. No observed changes in concentrations. No threshold available. No observed change in concentrations. 1 to 24% sites above threshold. No observed change in concentrations. 1 to 24% sites above threshold. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Insufficient data or no comparable data available. Decreasing concentrations. No threshold available.

Images H4: Exposure of wildlife to chemicals in the environment in England and, for some marine components the UK; up to 2019 where available

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Trend description for H4

i) PBT substances:

Downward trends are observed for polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in marine fish (dab) and for PBDEs and perfluorooctanesulfonic acid (PFOS) in harbour porpoise. These trends are particularly evident for PBDEs.

Exceedance of thresholds is most significant for mercury in the freshwater and marine environments, followed by PCBs in the marine environment. The result for mercury in dab may be over-precautionary for reasons given in the supporting report.

ii) Heavy metals:

For heavy metals, downward trends are observed for nickel and zinc in sparrowhawks, although the data are only available up to 2014. There is an upward trend for nickel in dab, which is driven by eastern and southern coastal marine sites.

The exceedance of the nickel threshold in estuarine and coastal waters is only driven by one site. Zinc shows the highest rate of threshold exceedance of the metals in both freshwater and estuarine and coastal waters.

While the freshwater data for heavy metals show no change in concentrations from 2014 to 2019, these results can be split into 2 types: those for sites where the waters are affected by abandoned metal mines and those for sites in other locations. Cadmium and copper exhibit downward trends for the ‘other’ sites over the assessed time period. Lead, nickel and zinc concentrations show no statistically significant change over time at such sites. For waters affected by abandoned metal mines, none of the metals shows any statistically significant change in concentrations over time. However, their elevated levels of cadmium, copper, lead, and zinc mean that they comprise a high proportion of those overall sites above available thresholds. The exception is for nickel, where sites in ‘other’ locations comprise the majority of those at risk.

iii) Pesticides and biocides:

It is not possible to report on trends for pesticides and second-generation anticoagulant rodenticides (SGARs) with the available data to 2019. Risk is indicated for less than a quarter of sites or individuals considered for pesticides in water and SGARs in red kite.

Assessment of change

No assessment of change was undertaken for this indicator as a suitable time series is not yet available in the Outcome Indicator Framework.

Indicator Metadata