Scientists predict collapse of wildlife populations due to pollution from chemicals and waste

Date: 1 March 2019

The impact of pollution - from chemicals and waste - on wildlife is far-reaching and its consequences are likely to be lethal to many species. Even the world’s seemingly pristine habitats show signs of pollution from plastics, whilst one group of toxic chemicals – the Persistent Organic Pollutants or POPs – are by their very nature able to travel long-distances, ending up in remote regions far from industrialisation such as the Arctic.

Bird populations have long been known to be vulnerable to chemical pesticides, with the renowned writer Rachel Carson first bringing public attention to this in her seminal work from 1962, “Silent Spring”. Last year’s State of the World’s Birds report[1] by Birdlife International found that more than 1,400 species, or 1 in 8 of all bird species, are currently threatened with extinction, with more than 1,000 species at risk from agriculture and a further 200 from pollution. Bees and other pollinators are similarly impacted by chemical use, with UN Environment[2] recently noting that more than 75% of food crops and 90% of wild flowering plants are dependent upon pollinators for their existence and that the application of chemicals such as neonicotinoids is strongly implicated as adversely affecting bees and other pollinators.

Sadly, the body of evidence for such impacts is growing. Recently, scientists[3] concluded that entire populations of killer whales, for example, are threatened due to their exposure to just one group of POPs, known as PCBs - or polychlorinated biphenyls. Before being controlled under the UN’s Stockholm Convention when it entered into force in 2004, PCBs were widely produced and used in electric transformers and capacitors, and as additives in paint, carbonless copy paper, and plastics, especially in North America, Europe and Japan. Once released, PCBs found their way into the food chain and have accumulated in the bodies of killer whales or orcas (Orcinus orca sp.) where they have impacted upon the whales’ immunity and reproductive systems, leading to lower calving rates. Concentrations of chemicals such as PCBs may be transmitted from mothers to young already in the womb through the placenta, passing the toxic legacy on to future generations.

As a result, populations of whales found in Brazilian, Japanese, Pacific north-west of America, United Kingdom, and northern Pacific (Biggs) waters are all tending towards complete collapse, as a result of PCB contamination[4].

That PCBs were already banned in many countries several years ago shows how persistent these chemicals are, underlining the need for the fullest possible implementation of the Stockholm Convention, and its sibling conventions dealing with chemicals and waste, including the Rotterdam and the Basel conventions.

The wide geographical extent of PCB contamination also stresses the need for global collaborative action towards the sound management of chemicals and waste. The international community will soon come together at the fourth UN Environment Assembly (UNEA-4: Nairobi, 11 to 15 March 2019), and again at the joint meetings of the conferences of the Parties to the Basel, Rotterdam and Stockholm conventions (Triple COPs: Geneva, 29 April to 11 May 2019) to consider proposals for strengthening international governance to deal with pollution, including from plastic waste and from POPs. The theme of the next Triple COPs is “Clean Planet, Healthy People: Sound Management of Chemicals and Waste”.

For example, Parties to the Stockholm Convention will discuss listing the industrial chemical perfluorooctanoic acid (PFOA), its salts and PFOA-related compounds, widely used in domestic non-stick cooking ware and food-processing appliances, surface treatment agents in textiles, paper and paints, and in firefighting foams. The chemical is known to be toxic to humans and the environment with links to major health issues such as kidney cancer, testicular cancer, thyroid disease, and pregnancy-induced hypertension[5]. Listing PFOA under the Convention would require its elimination, thus protecting current and future generations of people and wildlife from its harmful impacts.

Notes for Editors:

The Stockholm Convention on Persistent Organic Pollutants is a global treaty to protect human health and the environment from chemicals that remain intact in the environment for long periods, become widely distributed geographically, accumulate in the fatty tissue of humans and wildlife, and have harmful impacts on human health or on the environment. Exposure to Persistent Organic Pollutants (POPs) can lead to serious health effects including certain cancers, birth defects, dysfunctional immune and reproductive systems, greater susceptibility to disease and damage to the central and peripheral nervous systems. Given their long-range transport, global action is needed to protect citizens and the environment from POPs. In response to this global problem, the Stockholm Convention, which was adopted in 2001 and entered into force in 2004, requires its Parties to take measures to eliminate or reduce the release of POPs into the environment. As of today, this legally-binding Convention has 182 Parties, giving it almost universal coverage. To date, 28 chemicals of global concern have been listed under the Stockholm Convention.

For more information, please contact:

  • For Stockholm Convention, PCBs, and other POPs: or contact:
    Kei OHNO WOODALL, Secretariat of the Basel, Rotterdam and Stockholm Conventions (UNEP), Geneva: +41-79-233-3218, +41-22-917-78201,
  • For BRS conventions general media enquiries: or contact:
    Charlie AVIS, Public Information Officer (UN Environment), Geneva +41-79-730-4495

[1] Birdlife International, 2018, State of the World’s Birds 2017, available at:

[2] UN Environment, 2016, Pollinators under threat: So what? Foresight Brief no.11 available at:

[3] Desforges et. al., Science 361, 1373-1376 (2018) Predicting global killer whale population collapse from PCB pollution, available at:

[4] ibid