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Pollution is the presence in, or introduction into, the environment of a substance that can have harmful or poisonous effects.

This page provides a brief background to air and chemical pollution, the effects they can have on nature, and the work of JNCC’s Environmental Pollution team (EPT).

A logo illustrating the triple planetary crisis of pollution, biodiversity and climate change with arrows indicating they are all linked

The work of the Environmental Pollution Team (EPT) feeds into JNCC's seven strategic priorities, particularly:

  • Respond to the global biodiversity crisis.
  • Advise on policy to progress on nature recovery.
  • Align nature and climate change actions.

Additionally, the EPT's work links with wider priorities such as several of the United Nations (UN) Sustainable Development Goals (SDGs) and Defra's 25 Year Environment Plan (25YEP) indicators

  • The EPT’s work is applicable to a number of SDGs, including: 6 – Clean Water and Sanitation; 10 – Reduce Inequalities; 13 – Climate Action; 14 – Life Below Water; 15 – Life on Land; 17 – Partnerships.
  • The EPT’s work is applicable to 25YEP goals for: Clean air; Clean and plentiful water; Thriving plants and wildlife; and Managing exposure to chemicals. The 25 YEP is evaluated through indicators; those related to the EPT’s work include: A – Air; D – Wildlife; H – Biosecurity, Chemicals and Noise; J – Resource Use and Waste; K – International.

What is pollution?

Pollution is the introduction of contaminants into the environment that cause detrimental change. It can take the form of any substance or energy.

Pollution is listed by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) as one of the five main drivers of biodiversity loss. This is due to the ecotoxicological effects of pollution acting on species. Changes in the species present leads to ecosystem effects, such as changes in food web interactions and an altered species community structure (IPBES 2019). Pollution not only impacts biodiversity but exacerbates climate change, and vice versa.

JNCC's Environmental Pollution Team (EPT) focusses on air pollution (mainly the impact of nitrogen oxides and ammonia) and chemical pollution, both of which impact the environment.

Chemical Pollution

Broad classes of chemical pollutants include, but are not limited to:

  • Persistent Organic Pollutants (POPs) are recognised by the UN Stockholm Convention as causing adverse effects on humans and ecosystems and remain in the environment for prolonged periods of time. They are used in pesticides, agriculture, industrial processes and manufacturing. 
  • Emerging Contaminants include pharmaceuticals for humans, veterinary medicines, personal care products, and illegal drugs. Exposure of these chemicals can cause physiological changes, which impact species populations, reproduction and reduce biodiversity (Kuster and Adler 2014).  
  • Nutrients in excess arise from sources such as nitrate and phosphate fertilisers, sewage run-off, and animal manure. They can be washed away and enter rivers and coastal areas causing adverse effects on ecosystems. Such effects include eutrophication, poor water quality, harmful algal blooms, and the death of fish and other aquatic organisms (Howarth et al. 2000).  
  • Heavy Metals such as lead, chromium, arsenic, zinc, cadmium, copper, mercury and nickel, can contaminate soil, water and air. They arise from sources such as sewage sludge, dust from smelters, industrial waste, mining, chemical spills and oil spills. As heavy metal contamination is bio accumulative, the concentration increases through the food chain where exposure leads to major health concerns causing toxicity and reducing biodiversity (Wunana and Okieimen 2011).  

Air pollution

Air pollutants include sulphur dioxides (SO2), nitrogen oxides (NOx), ammonia (NH3), methane (CH4), carbon particulates (particulate matter, PM) and ozone (O3). SO2 is emitted from coal burning. NOx and NH3 are pollutants which arise from sources such as emissions from transport vehicles, power stations, industry, farm fertilisers and livestock. SO2 reacts with NOx and NH3 in the atmosphere to form particulate matter that has damaging health effects (WHO 2013) and contributes to the warming of the Earth.

An infographic displaying sources of air pollution emissions and the effects on the environment (such as eutrophication and biodiversity loss) as the pollutants transfer from air to land and waterbodies through wet and dry deposition

Figure 1: This infographic displays sources of air pollution emissions and the effects on the environment (such as eutrophication and biodiversity loss) as the pollutants transfer from air to land and waterbodies through wet and dry deposition.

NOx and NH3 in the atmosphere increases nitrogen in soils through deposition. This lowers soil pH and increases nutrient availability allowing fast growing species, such as nettles (Urtica dioica), to thrive while more nitrogen sensitive wildflowers, many of which prefer less nutrient-rich soil such as harebell (Campanula rotundifolia), are outcompeted.

When a species is outcompeted, its abundance decreases over time, reducing biodiversity, and it may be completely lost from that habitat. Nitrogen deposition can be attributed to loss of species richness of key plant communities in the UK by 33% (Payne et al. 2017).


Pollution, Climate Change and Biodiversity Loss: The Triple Planetary Crisis

The United Nations Framework Convention on Climate Change (UNFCCC) considers pollution one of the three interconnected planetary crises, along with climate change and biodiversity loss, which are placing global economic, environmental, and social well-being at risk (UNFCCC 2022). For example, research shows that climate change can increase the sensitivity of wildlife and ecosystems to chemical pollution, with associated impacts on human health (Fuller et al. 2022).

Furthermore, a change in climate will bring about more frequent and intense storm events (WHO 2020), which will lead to an increase in severe industrial chemical and waste spills. Fluctuating weather patterns will result in larger quantities of solid waste, such as plastics, and chemicals being washed into river systems and likely alter pest distributions, leading to greater incidences of pest and disease outbreaks and an expected increase in pesticide use.

Understanding of chemical changes, impacts on biodiversity, and the role of climate change is essential to providing solutions to the triple planetary threat and is embedded throughout the Environmental Pollution Team’s work.

Pollution, Biodiversity and Climate Change infographic, showing how the three are linked and impact the environment

Figure 2: This infographic displays how pollution, biodiversity and climate change are intertwined and their effects on the environment. A full sized version of the infographic is available to download (PDF format).


JNCC’s Pollution work

JNCC has three main work areas: UK Air Pollution, UK Chemicals, and International Pollution.

JNCC works collaboratively with other organisations to provide scientific evidence and advice to the UK government. We are working on several projects, both within the UK and internationally, that focus on air pollution and the wider management of chemicals in the environment.  

UK Air Pollution

The EPT's air pollution work includes: 

UK Chemicals

The EPT's chemical pollution work includes: 

  • Supporting development of the H4 indicator (Exposure and adverse effects of chemicals on wildlife in the environment), to show how the exposure of harmful chemicals to wildlife on land or in water is changing over time.
  • Developing a System Level Indicator project, which aims to gather existing data and integrate it to produce a communication tool to show the state of the environment in relation to chemical pollution.
  • Establishing an Inter-Agency Chemical Group (IACG) as a method for connecting conservation bodies: for knowledge sharing, co-ordination and development of UK level advice, shared evidence projects and initiatives relating to chemical pollution and conservation.

International Pollution

The EPT's international work includes: 

  • Working internationally with partners in South Africa on an Official Development Assistance (ODA) Environmental Pollution Programme (EPP) with the Department of Environment Food and Rural Affairs (Defra). This programme supports the low- to middle-income countries of South Africa and Vietnam to reduce pollution and manage chemicals across a range of projects in each country.
  • Provision of advice to Defra on the scientific development of the global United Nations Science Policy-Panel that aims to enhance the sound management of chemicals and waste to prevent pollution.


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