Toxic chemicals of fireworks can harm your health, researchers warn

Fireworks are a staple for festive periods such as the 4th of July and New Year's Eve.

But researchers have found that fireworks can contain metals such as copper and even lead, which can lead to air pollution and depleted lung defenses. 

Fireworks have even been reported to disturb birds, startling them and sending them flying from their roosts, disoriented in the darkness and colliding with objects.

According to Dr Gary Fuller, a lecturer in air quality measurement at King's College London, tiny metal particles in firework smoke can lead to air pollution problems. 

He told DailyMail.com: 'Fireworks are a real dilemma for me.

'They are great fun to watch but they pollute our air with some of the very same pollutants that we go to great lengths to clean from factory chimney emissions. 

'These include copper, barium, strontium and perchlorates. 

'Guy Fawkes night in the UK is often the most polluted day of the year. 

'Firework pollution can linger in a town for days and last year’s Diwali heralded the start of a serious smog across many of India’s major cities.'

For example, a 2010 study found that short term peaks of particulate matter from firework events in London have been associated with negative impacts on respiratory and cardiovascular health. 

Researchers collected air quality samples 24 hours after two major festivals: Guy Fawkes Night and Diwali, finding that these increases in particulate matter exceeded regulatory limit values. 

Another study found that fireworks led to increases in perchlorate concentrations in adjacent lakes for 20 to 80 days following 4th of July fireworks displays.

Perchlorates - which are chemicals used in explosives - are a concern because ingestion can lead to adverse health affects such as interference with the production of thyroid hormones required for normal metabolism and the development of mental function. 

Dr Terry Gordon, a professor at NYU's Department of Environmental Medicine, told the DailyMail.com that he and his colleagues recently conducted a study where he analyzed the components of a dozen firework samples used in pyrotechnic firework displays.

He said that fireworks purposefully put metals in the air, so there has been a lot of research into perchlorates and their effect on air. 

Dr Gordon and his colleagues studied 12 different types of fireworks and set them off under controlled conditions in a stainless steel chamber, and considered particles which were of a size that could enter the lungs.  

They then tested the chemicals in mice, finding that different chemicals led to different levels of effect.

The most toxic chemicals the team discovered were copper, titanium, strontium and lead. 

According to Dr Gordon, these chemicals caused increased oxidative stress to cells - when cells overproduce free radicals, chemicals which can eventually lead to chronic diseases such as cancer, diabetes, rheumatoid arthritis, heart attack, chronic inflammation, stroke and other degenerative diseases. 

Dr Gordon did however point out that his study, which has yet to be published, indicates correlation between these chemicals and their toxic effect, but it does not show causation. 

This means that certain chemicals in fireworks are associated with negative health effects, but there is no proof that they cause these effects. 

But fireworks don't just increase air pollution to dangerous levels - they also affect birds. 

According to The Royal Society for the Protection of Birds, setting of fireworks close to nesting and roosting birds can cause disturbance. 

The organization advises against launching fireworks near to sensitive wildlife areas, such as nature reserves and nesting grounds for wild birds. 

For example, during a New Year's Eve fireworks display in Beebe, Arkansas in 2010, up to 5,000 red-winged blackbirds fell out of the sky and died.

Beebe is a roosting ground for blackbirds, and during the night when the fireworks started, they may have been startled and their poor vision at night could have led them to be disoriented. 

Follow NEWS.am Medicine on Facebook and Twitter