Fireworks, while visually captivating, release substances that negatively impact the environment. These displays introduce pollutants into the air, water, and soil, contributing to contamination. The effects extend beyond immediate disturbances, influencing ecosystems and affecting living organisms. This article explores the chemical components and the environmental and health concerns from their use.
Chemical Components and Pollutants
Fireworks display vivid colors due to various metal compounds, often metallic salts. Strontium creates red, copper yields blue, and barium provides green, while sodium salts produce yellow or orange. Aluminum, magnesium, and titanium are used for white or silver effects.
Their propulsive force originates from black powder, a blend of potassium nitrate, sulfur, and charcoal. Oxidizers, such as perchlorates, are added to facilitate the explosive reaction. Upon ignition, these chemicals combust, releasing pollutants.
Metals like barium, copper, and strontium are emitted as fine particles. The burning process generates gases, including various sulfur and carbon compounds, and additional particulate matter. Some illegal fireworks may contain lead.
Atmospheric Contamination
Atmospheric contamination is a primary concern with fireworks, largely due to fine particulate matter. These microscopic particles, especially PM2.5, are easily inhaled and penetrate deep into the respiratory system. Studies indicate PM2.5 concentrations can increase significantly, sometimes up to eight times, during and immediately after displays. For example, air pollution levels increased by an average of 42% on the Fourth of July in the US.
While elevated levels often return to background within 24 hours, their short-term intensity burdens the environment. Such high concentrations reduce air quality and visibility, with reports showing decreases up to 92%. This smoke and haze can also travel for miles, affecting broader regions.
Fireworks also release harmful gases, including sulfur dioxide, nitrogen oxides, carbon monoxide, and carbon dioxide. Sulfur dioxide and nitrogen oxides, when mixed with other atmospheric chemicals, can form acid rain, harming ecosystems.
Water and Soil Contamination
Firework residues, including unburnt chemicals and debris, can contaminate water bodies and soil. Heavy metals like barium, copper, and strontium, initially airborne, eventually settle onto land and into aquatic environments. These metals can leach into soil, altering nutrients, or be washed by rainfall into rivers, lakes, and oceans.
Perchlorates, used as oxidizers, are concerning due to their water solubility and persistence. Elevated concentrations have been found in surface water and groundwater near display sites, risking aquatic ecosystems and drinking water supplies.
Beyond chemical contamination, fireworks create noise pollution. Explosive sounds can exceed 85 decibels, a level potentially harmful to human hearing. This intense noise disturbs wildlife, contributing to environmental stress.
Biological and Health Impacts
The pollutants from fireworks affect human health and wildlife. For humans, inhaling fine particulate matter and gases can cause respiratory issues like coughing, lung irritation, and difficulty breathing. Vulnerable groups include those with asthma or COPD, children, and the elderly. Exposure may also lead to eye irritation or, in severe cases, increased risks of heart attacks.
For wildlife, intense noise creates significant stress, panic, and disorientation. Animals may flee habitats, disrupting natural behaviors such as feeding and breeding, potentially causing injuries or nest abandonment. Ingestion of contaminated water or food sources also poses a threat.