Pollution’s double assault on wildlife: How air and noise pollution are pushing wildlife into distress

As cities wake up to thick layers of smog, pollution is usually discussed through the lens of human health. Hospitals report breathing difficulties, authorities issue warnings and residents are advised to limit outdoor activities. But there is another group of living beings exposed to the same polluted environment, without masks, air purifiers or the option of staying indoors: animals.

From birds flying over congested roads to stray dogs searching for food, from insects navigating urban gardens to aquatic animals exposed to pollutants entering water bodies, environmental pollution is changing the conditions in which wildlife lives.

The problem does not end with the air people breathe. Human-made noise, often dismissed as an unavoidable part of urban development and celebrations, is emerging as another serious threat. Traffic, construction, aircraft, industrial activity, loudspeakers and fireworks are interfering with the ways animals communicate, find food, reproduce and recognise danger.

Together, air and noise pollution are creating an increasingly hostile environment for wildlife.

What does rising AQI mean for animals?

The Air Quality Index (AQI) is a measurement used to communicate the level of air pollution and its potential health risks. However, it is primarily designed around human exposure. Animals do not have a separate AQI warning system, even though they breathe the same air.

One of the biggest concerns is particulate matter, particularly PM2.5 and PM10. These are tiny airborne particles produced by sources such as vehicle emissions, industrial activities, construction dust, biomass burning and fireworks.

PM2.5 particles are particularly concerning because their small size allows them to travel deep into the respiratory system. Depending on the species, exposure can affect respiratory health, trigger inflammation and contribute to wider physiological stress.

Birds are especially interesting in this context. Their respiratory systems are highly specialised to support the energy demands of flight. They have a system of air sacs that helps maintain continuous airflow through their lungs. This does not make them immune to polluted air. Exposure to airborne contaminants can affect respiratory function and other biological processes.

A 2023 review examining the effects of air pollution on terrestrial birds found that most of the studies reviewed identified at least one trait negatively associated with pollution. However, researchers also highlighted gaps in the evidence and differences between species and habitats.

For mammals, including urban wildlife, polluted air can mean prolonged exposure to particles and gases while searching for food, shelter or mates. Animals living near roads, factories and construction sites may face repeated exposure.

The effects are not restricted to breathing. Air pollution can also affect vegetation, soil and water, indirectly changing the availability and quality of food and habitats. Pollutants deposited on plants and water bodies can enter food chains, exposing animals through feeding and other forms of contact.

The post-Diwali pollution question

The issue has become particularly relevant in India during the post-Diwali pollution season.

Delhi's air quality deteriorated sharply following Diwali celebrations on November 8, 2026. The city's AQI reached 372 at 10 am on November 9, placing it in the very poor category, according to reports citing official monitoring data. Although readings subsequently improved, pollution remained a major concern.

Firecracker emissions added to an already polluted atmosphere, which was also affected by vehicle emissions, industrial pollution, construction dust, crop-residue burning and unfavourable weather conditions.

For animals, the consequences can extend beyond the hours of celebration. Pollutants do not disappear immediately after fireworks stop. Particles can remain suspended in the atmosphere or settle on surfaces, vegetation and water.

Street animals, birds and other wildlife living in these environments cannot simply move away from every polluted area. Urban birds may continue searching for food around roads and buildings, while stray animals remain exposed to emissions from traffic and other sources.

Importantly, the impact of a particular AQI reading on an animal cannot be calculated directly from the human health category. Exposure duration, pollutant concentration, species, age and existing health conditions all matter.

The other pollutant we rarely discuss: Human-made noise

Air pollution may be visible through smog, but noise pollution is an environmental threat that often goes unnoticed because its effects are not immediately visible.

A major new scientific finding published in the journal Science on November 5, 2026, has brought this issue back into focus.

Researchers Hansjoerg Kunc and Rouven Schmidt from Queen's University Belfast analysed 214 experimental studies involving 177 aquatic and terrestrial species across six continents.

Their findings were significant: human-generated noise altered at least one physiological, developmental or behavioural characteristic in 80 per cent of the species examined.

This is an important distinction. The figure does not mean that 80 per cent of all animal species worldwide have been studied and found to be distressed. It means that 80 per cent of the 177 species included in the research showed measurable changes in at least one of the examined areas.

The findings nevertheless demonstrate how widespread the effects of human-generated noise can be.

How does noise interfere with animal behaviour?

For animals, sound is not simply background noise. It is an essential part of survival.

Birds use calls to attract mates, defend territories and warn others about approaching predators. Many mammals depend on sound to communicate, locate food and remain aware of their surroundings. Underwater, fish and marine mammals also use sound for communication, navigation and detecting changes in their environment.

Human-generated noise can interfere with these natural signals.

Traffic, aircraft, construction machinery and industrial activities can make it difficult for animals to hear one another. Scientists call this auditory masking, where unwanted sound covers important biological signals.

For example, birds living near busy roads may alter the timing, frequency or volume of their calls to communicate despite background traffic. However, changing their calls does not necessarily eliminate the problem.

Noise can also interfere with predator-prey interactions. An animal that cannot hear an approaching threat may become more vulnerable. Similarly, predators may struggle to locate prey when environmental noise masks important sounds.

Continuous exposure can also create physiological stress. Animals may spend more time remaining alert and less time feeding, resting or engaging in other essential activities.

The 2026 study also reported effects on fitness and abundance, as well as disruptions to predator-prey interactions. This suggests that the consequences of noise pollution can extend beyond individual animals and influence entire ecosystems.

Firecrackers, loud celebrations and animals

The relationship between noise pollution and animal welfare becomes particularly visible during festivals and public celebrations.

Firecrackers produce sudden, unpredictable bursts of sound. Unlike humans, who may understand that these sounds are temporary celebrations, animals do not interpret them in the same way.

Dogs and cats may display fear, agitation, hiding behaviour or attempts to escape. Birds can become startled, abandon resting places and experience disturbances in their normal activity patterns.

Wild animals may also respond by moving away from noisy areas, sometimes leaving otherwise suitable habitats.

The effects depend on the species, intensity, duration and frequency of exposure. Not every animal responds identically, but repeated disturbance can make it difficult for wildlife to maintain normal routines.

A 2025 systematic review of research on airborne human-generated noise identified 863 relevant articles, including primary studies, reviews and meta-analyses. It found that birds and mammals dominated the existing research, while several other groups, including reptiles and arachnids, remained comparatively understudied.

This is important because the problem may be broader than the available research currently captures.

When two forms of pollution become one ecological crisis

Air pollution and noise pollution are often treated as separate environmental problems. In reality, they frequently originate from the same human activities.

Road traffic releases pollutants while producing continuous noise. Industrial areas generate emissions and mechanical sound. Construction projects create dust while disturbing nearby habitats. Large celebrations can combine airborne pollution with sudden, intense noise.

Their combined effects deserve greater attention, although scientists still need more research to understand how simultaneous exposure affects different species.

An animal living in an urban environment may face several pressures at once: polluted air, shrinking green spaces, artificial lighting, constant traffic and disrupted natural soundscapes.

Over time, these pressures can influence where animals live, how they behave and whether they can successfully reproduce.

Can wildlife be protected?

Addressing the problem requires more than temporary restrictions during festivals or emergency measures when AQI levels rise.

Cleaner transport, stricter industrial emission controls, better construction practices and the protection of urban green spaces can help reduce exposure to air pollution.

Noise pollution also needs to become part of environmental planning. Quieter transport systems, regulated construction hours, responsible use of loudspeakers and protection of natural habitats can help preserve soundscapes.

Wildlife conservation must therefore move beyond protecting forests and counting endangered species. It must also consider the quality of the air animals breathe and the sounds that surround them.

Humans have the ability to monitor pollution, close windows and seek cleaner environments. Most animals do not have those choices.

The real question is no longer whether pollution affects wildlife, but how much of the natural world is being forced to adapt to an environment increasingly shaped by human activity.