Happy Diwali (Deepavali)!
No doubt Diwali will be celebrated across the world, as are many important events on the calendar, through the setting off of lots of fireworks. The spectacles produced are brilliant, of course ~ but they are costly, and not only in terms of the cost of the fireworks and the impacts on our pets. Fireworks are also highly polluting and have the potential to impact negatively environmental quality and our health.
Aside from the littering caused by all those spent fireworks – no surprises there, what goes up has to come down – ever wondered what all those bright colours are formed from? They are formed from the high temperature combustion of compounds containing heavy metals (“heavy metal salts”). Sparkling green colours are produced by barium chloride, blue is produced by copper chloride. Strontium carbonate is used to produce red fireworks, calcium chloride ~ orange fireworks, sodium nitrate ~ yellow fireworks. Purple fireworks are typically produced by use of a mixture of strontium (red) and copper (blue) compounds. The list goes on and on ….
Combustion also yields other pollutants, notably fine particulate matter (including PM10 and PM2.5, but no doubt even finer particles too), sulfur dioxide (SO2), persistent organic pollutants (PoP) polycyclic aromatic hydrocarbons (PAHs) and highly toxic dioxins. None of these are good for us. And that is not all, of course we have developed fireworks that make louder bangs and travel to higher altitudes in the sky. This is all based on chemistry and chemical reactions, but also involves some very old technology – gunpowder, which is believed to have been invented in China over 1000 years ago! Thus as Licudine et al. (2012) reported in the journal Public Health Reports, based on their study of air pollution linked to new year firework celebrations on Hawaii (see paper linked below), “chlorates or perchlorates can be used to achieve noise levels equivalent to trinitrotoluene and result in more violent explosions than traditional nitrates … Lead (Pb) salts are widely used as igniters to initiate fireworks explosions. Manganese (Mn) and Mn dioxide serve as fuel and oxidizer for brighter lights, chromium (Cr) is used as a burn rate catalyst for propellants,and nickel (Ni) acts as an electric firing device for fireworks.” The health effects of heavy metals are well-known, and many of the emissions from fireworks persist in the environment long after the spectacle of the display is over. The authors go on to state that “perchlorates have been associated with thyroid problems, and toxic byproducts (e.g., dioxins) could be produced as a result of atmospheric reactions between metal oxides and organic fuels.”
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Open in new tab Licudine et al. (2012) is not the only study on fireworks as a source of environmental pollution. In fact there have been many such studies. One of these investigated air quality in Delhi, India, during the Diwali celebrations. Delhi is already one of the world’s most polluted cities, particularly during the Northern Hemisphere autumn and winter months (which is when Diwali takes place) when local weather conditions and the burning of fossil fuels and biomass for heat, transport and cooking conspire to produce some of the poorest air qualities ever recorded globally. The study by Peshin et al (2017 – and see link below to the paper) recorded substantial increases in SO2, nitrogen dioxide (NO2) – a greenhouse gas and cause of environmental acidification, ozone (O3), fine particulate matter (including black carbon, or soot) and trace metals during firework displays associated with Diwali celebrations.
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Similar findings have also been reported for Jamshedpur in the east Indian state of Jharkhand, suggesting that firework-related pollution is a widespread problem in India during Diwali celebrations (Ambade, B. The air pollution during Diwali festival by the burning of fireworks in Jamshedpur city, India. Urban Climate 26, 149-160). The setting-off of firecrackers is highlighted in this article as a particularly rich source of pollution, as it is here (for Delhi) and here (for China).
An even more recently published article – just out in the Journal of Cleaner Production, emphasises that “[r]ecreational fireworks use causes some of the most extreme urban particulate matter pollution: Hourly peaks over 1000 ug/m3 PM10 have been measured during the Chinese New Year and Indian Diwali festivals …. [f]ireworks plumes can be detected over a long range, between regions and countries, in the form of elevated particulate matter (PM10 and PM2.5) and water-soluble potassium … [i]n Western Europe, fireworks celebrations have contributed to significant annual atmospheric metal emissions, to the urban background of trace metals, and to a localized perchlorate pollution in surface and groundwater” (Andradottir and Thorsteinsson, 2019). Unfortunately this article is not available for public download, but it is accessible via NUS’s excellent library in digital form: Andradottir, H.O. and Thorsteinsson, T. (2019) Repeated extreme particulate matter episodes due to fireworks in Iceland and stakeholdersā response. Journal of Cleaner Production, 236, 11711.
One of the points raised by Andradottir and Thorsteinsson (2019) is the “passiveness” of the general public when it comes to the pollution and health risks of firework displays. The authors of the paper claim that this in part stems from a lack of awareness of the link to pollution. The authors argue that the general public should be made more aware and that the purchasing of less environmentally damaging fireworks should be encouraged (for example, Disney uses fireworks that are propelled by compressed air rather than gunpowder – why cannot others follow suit?).
We need also to be mindful of the costs of producing and transporting fireworks to their point of use, and the risks posed to those involved in their manufacture. An estimated 90% of the world’s fireworks are manufactured in China – often in rural areas, with women predominantly involved in actually making the fireworks, handling dangerous chemicals with little formal training. Accidents happen, often with lethal consequences – as is evident from the webpage linked here. Accidents are also commonplace in Sivakasi, the city in Tamil Nadu that is commonly regarded as India’s “fireworks capital“. Whoever thinks about the conditions fireworks are produced under, and what health-threatening substances and practices those involved in the manufacture of fireworks are exposed to, when purchasing fireworks or going along to a display? Do we really think that those toxic substances used in manufacturing never leak out into the environment even before the fireworks are used? And what about all that packaging that comes with fireworks – where does that all end up?
It could be argued that what we are actually celebrating through our firework displays is our reckless disregard for our environment, for the economically marginalised and, ultimately, for ourselves.
It’s sad that the entertaining and beautiful display of fireworks can in some ways cause us to meet an early grave. I’ll remember that the next time I admire some pretty sky flowers š