Fireworks: Pretty for The Eyes, Bad for the Environment

Who doesn’t love watching fireworks? Burst of colors up on the night sky, a feast to the eye. 

Fireworks at night
Photo credit: MIO ITO/Unsplash

However, have you ever wondered about the composition of fireworks themselves? How can a single firecracker emits so many colors, sometimes even in a very elaborate and intricate form, when being lit up?

And what about the aftermath? Do the exploding substances just vanished into thin air? Or did they actually left a mark, one that is invisible to the eye, but is actually concerning?

Fireworks by the city.
Fireworks in the middle of the city. Photo credit: CHUTTERSNAP/Unsplash

We’re not trying to be a party pooper here, we just believe that we always need to evaluate the way we do things and how it impacted our already fragile environment. Apparently, fireworks did, albeit not explicitly.

Why Are Fireworks Harmful?

So basically, a firework is a small pyrotechnic missile that explodes in a very specific way, creating loud explosions and bursts of brightly colored light up in the air.

The colors of fireworks are the results of chemical and physical reactions, that is, fireworks’ colors derived from solid metal salts and chemical explosives that create colors when heated to certain temperatures.

The chemistry of fireworks color. Source:

Different metal compounds give different colors. For example,

  • Lithium (Li) salts produce pink color,
  • Sodium (Na) salts for the color of orange or yellow,
  • Copper (Cu) and barium (Ba) salt for green or blue, and
  • Calcium (Ca) or strontium (Sr) for red

The metal salts and explosives in the fireworks undergo chemical changes when combined with oxygen (combustion). This chemical reaction then releases greenhouse gases such as carbon dioxide, carbon monoxide, and nitrogen.


Moreover, the metal salts from which fireworks gain their beautiful color do not just ‘burn up’. They are still metal atoms, and many of them end up as aerosols that pollute the air, and eventually our water and soil too.

And, when inhaled or ingested, these metals can cause a huge variety of short- and long-term reactions, ranging from vomiting, diarrhea, or asthma attacks, to kidney disease, cardiotoxic effects, and a variety of cancers.

The Link between Fireworks and Air Pollution

Fireworks directly affected the surrounding air, and this is evident when we compared the air quality before and after fireworks take place using a system called the Air Quality Index, which measures daily concentrations of air-borne pollutants.

The chemistry of firework pollution. Source: Compoundchem,com

The index values of air pollution range from 0 to 500 and the score above 401 is classified as ‘severe’, meaning that it can seriously affect healthy people and those with existing respiratory illnesses.

One event that is often used as a study case to measure the connection between fireworks and air pollution is the Diwali Festival in India. Diwali itself is a Hindu holiday that falls in autumn in India, where it is known as the ‘celebration of lights’ and is celebrated using fireworks, lots and lots of it.

Diwali Festival 2017
Diwali Festival 2017. Source:

The research revealed that during the Diwali Festival back in 2015, The PM10 concentration was 81% higher than other days and 3.1-times higher than the Indian National Ambient Air Quality Standards.

Furthermore, the concentrations of metals, cations, and anion increased by 51%, 72%, and 77%, respectively. Lastly, the higher concentrations of metals during the Diwali period resulted in a 0.5% increase in the hazard index.

Similarly, during the Diwali Festival in 2019, the concentrations of airborne pollutants spiked higher than normal in already severely polluted Dehli. According to India’s Central Pollution Control Board, the emissions caused by the festival even surpassed the Air Quality Index at 500 in several parts of that city, including the international airport.

Let’s take a look at another case, this time it’s a 3-week study in London, which covers two major festivals (Guy Fawkes Night and Diwali ) that are celebrated using pyrotechnic. The study revealed an increase of nitric oxide (NOx) and sulfur dioxide (SO2) gasses, which are primary contributors to acid rain as well as greenhouse gasses. In addition, the study also found elevated PM concentrations, and trace concentrations of heavy metals, specifically strontium (Sr), magnesium (Mg), potassium (K), barium (Ba), and lead (Pb). 

Effects on Human Health

A 2010 study observe the concentration of air pollutants such as SPM (suspended particulate matter), PM10, PM2.5, SO2 and NO2 for six consecutive days during the Diwali Festival in Salkia, a densely populated residential area near Kolkata, India.

The research used epidemiological data to estimate the likely health impacts from fireworks pollution, and the results is that the relative risk of cardiovascular mortality increased to 125.11% and the relative risk for cardiovascular morbidity increased by 175.16% over a regular winter day.

Moreover, hospital admissions for asthma and other breathing problems peak the day following a fireworks display.

Similarly, in the 2015 Diwali Festival, there was an increase in hospitalizations for respiratory symptoms during firework periods compared to non-firework periods

Finding Better Options

More studies might need to be conducted in order to further assess the possibly wide impacts of fireworks to the environment and human health. However, existing studies make it clear that fireworks are not harmless after all.

But how does one celebrate, say, New Year’s Eve, without fireworks? Well, there are always alternatives if we really do want to change. For instance, a fountain show, a light show (keep in mind that this will consume lots of electricity), or just a humble dinner or picnic with families, blowing trumphets and saying goodbyes to the passing year while staying at home. (Read also: The not-so-beautiful effect of sky lanterns and balloons)

It might not be now, perhaps not even in the near future. But we aspire (and hopeful) to see a future where fireworks are not the only way to celebrate New Year or other major festivals.


Environ. Sci. Technol. 2010, 44, 21, 8295–8301Publication Date: October 1, 2010

Licudine, J. A., Yee, H., Chang, W. L., & Whelen, A. C. (2012). Hazardous Metals in Ambient Air Due to New Year Fireworks during 2004–2011 Celebrations in Pearl City, Hawaii. Public Health Reports, 127(4), 440–450.

Rajyalakshmi Garaga, Sri Harsha Kota; Characterization of PM10 and Impact on Human Health During the Annual Festival of Lights (Diwali). Journal of Health and Pollution 1 December 2018; 8 (20): 181206. doi:

THAKUR, B. et al.Air pollution from fireworks during festival of lights (Deepawali) in Howrah, India – a case study. Atmósfera [online]. 2010, vol.23, n.4, pp.347-365. ISSN 0187-6236.