Many occasions call for celebrations with fireworks displays. Many cultures and countries use fireworks as a centerpiece of celebration, with almost half the year containing one fireworks holiday per month.
Chances are that you’ve also been confused by the sudden sound of fireworks in your neighborhood, as people host private displays for birthdays, parties, or delayed holidays.
Fireworks may look pretty but they’re not eco-friendly, with a sizable environmental impact.
Are fireworks environmentally friendly?
Fireworks rely on chemical reactions to function, and the cheapest chemicals are always synthetic because they’re easier to make and use.
In 2020, over 404.5 million pounds of fireworks were either bought by consumers or used in fireworks displays. The number of fireworks consumed each year has steadily risen – it’s more than doubled in twenty years.
The reason for the huge surge in sales of fireworks is likely due to global lockdowns during the COVID-19 pandemic and lack of public displays, but the jump in the last two decades is immense.
Displays at home are less accessible and regulated than public displays, which need to abide by health and safety guidelines or involve professional pyrotechnicians.
Many home displays result in more widespread effects on the environment, health, and wildlife.
Do fireworks pollute the environment?
Fireworks use charcoal and sulfur fuel with a perchlorate oxidizer, binders, colorants, and propellants. The fuel is gunpowder – made from charcoal, sulfur, and saltpeter (potassium nitrate) – though the health hazards associated with sulfur have resulted in sulfurless powder that uses extra potassium nitrate.
Sulfur is both harmful to the environment and health.
Fireworks release sulfur dioxide, which is directly linked to damaging respiratory systems, making it hard for people to breathe. High concentrations of sulfur dioxide can also damage trees and contribute to acid rain.
Thanks to charcoal, fireworks also release carbon dioxide and carbon monoxide into the atmosphere.
The chemical reaction of gunpowder further adds to greenhouse gases by releasing nitrogen.
The Global Warming Potential of nitrous oxide is almost 300 times that of carbon dioxide. Potassium nitrate isn’t the only nitrogen used in fireworks either, with yellow fireworks using sodium nitrate for its color.
Other metal salts used to color fireworks include strontium carbonate, calcium chloride, barium chloride, and copper chloride, with many combinations between them. Chloride is known to be toxic to aquatic life, with even low concentrations impacting freshwater ecosystems.
Perchlorate oxidizers release oxygen to help the combustion reaction within fireworks, and when it falls back to the ground it can contaminate water, affecting both aquatic life and drinking water.
A study into perchlorate’s contamination of pond water found that concentrations of perchlorate could increase to as much as 1,480 times higher than baseline values following fireworks displays.
Ingesting perchlorate is known to decrease thyroid hormone production, which can affect the growth and development of central nervous systems in fetuses and infants.
Fireworks essentially release a “cocktail of chemicals into the atmosphere” that pollute both air and water. While scientists are working on reducing the amount of polluting chemicals used by fireworks, it’s clear that every ingredient in fireworks has some harmful impact on the environment.
It’s not only chemicals that directly pollute the environment either.
Particulate matter, which is small particles in the air made up of microscopic solids and liquid droplets, is also a pollutant. It affects air quality, even though inhalable particles and fine inhalable particles are so small that they can only be detected with an electron microscope. Particulate matter can get into the lungs and bloodstream, potentially causing serious health problems.
A review into the impact of fireworks on particulate matter found that this pollution can contribute to high concentrations of particle pollution. Exposure to particulate matter can cause adverse health effects.
How fireworks affect wildlife and pets
Unlike humans, animals aren’t able to tell the sound of fireworks is harmless, with many perceiving the noise and unpredictability of fireworks as being a threat. Dogs are particularly known to react to fireworks, either by barking or hiding.
According to the RSPCA, around 62% of dogs, 54% of cats, and 55% of horses show distress during fireworks displays.
Pets aren’t the only ones affected either.
Farm animals and wildlife can be easily frightened, as the bright lights and loud noises startle them. This can lead to them injuring themselves in their panic.
Birds have even been found to abandon their nests.
The stress caused by fireworks displays can result in panic, which can extend into behavioral problems and a phobia of loud noises.
Repeated and frequent exposure to fireworks can increase the amount of panic an animal undergoes. This distress can also lead to health problems, such as skin conditions, chronic stress, and decreased lifespans.
Animals in zoos are particularly disturbed by the noise of fireworks, with animals like rhinos and cheetahs displaying signs of stress.
Fireworks can emit sounds of between 150 to 175 decibels on average, which is louder than a gunshot. By being in close proximity to fireworks, irreparable damage can be done to the hearing organs of animals, resulting in loss of hearing and tinnitus even in humans.
Do fireworks kill birds?
Birds are one of the most vulnerable animals to fireworks, as the noise can cause tachycardia or death by fright due to the stress. They may also abandon their nest or habitat, which could cause them to lose valuable food sources, eggs, or other necessities in life.
Disorientation caused by fireworks can also result in birds flying into buildings or out to sea. While this is similar to their behavior during thunderstorms, successive fireworks across multiple nights may scare birds away from their nesting grounds and result in their young starving.
In 2011, thousands of birds fell out of the sky on New Year’s Eve in Arkansas. Tests on the red-winged blackbirds found that the birds died due to blunt-force trauma. The Arkansas Game and Fish Commission explained that the loud noises of the fireworks “caused the birds to flush from the large roost”, and due to their poor night vision, they may have crashed while flowing at a lower altitude than usual.
While more research needs to be done to determine how dangerous fireworks are for birds, many animal rights groups globally warn of their potential impact on animals.
Why do fireworks scare pets?
While pets are generally kept inside during nights associated with fireworks, their keen hearing can detect noises above human hearing ranges. Dogs can hear up to 60,000hz, three times that of humans, and this may be one reason for how affected dogs are by fireworks.
The sudden and unpredictable sound of fireworks frightens many dogs because the source can’t be identified. Without being able to identify the source of the noise, dogs cannot escape from the noise, which they perceive as a threat.
Older dogs are often more fearful of loud noises, and this anxiety can worsen each year. My own dog’s anxiety around the sound of fireworks has intensified as he’s gotten older.
Horses appear to feel threatened due to the sound of fireworks because of their hypervigilance. This can result in them panicking and attempting to flee. Around 26% of horses frightened by fireworks are injured in their attempts to flee, especially by trying to jump fences or running into roads.