4 Pollutants That Come From Landfill Sites

When waste is sent to landfill, it is compacted in the plastic bags in which it arrives and deposited into the ground. Over time, the site will gradually fill up with waste in this way, until it reaches capacity. At this point, it is covered over by a watertight barrier made from a mixture of clay and rubber. Soil and dirt is piled atop this surface, before grass is planted to prevent soil erosion.

Despite these measures, various pollutants can still leach out from the landfill and into the soil, groundwater and air nearby. This can not only compromise the environmental health of the surrounding area and potentially endanger the human population exposed to the contamination, but also exacerbate issues like climate change and global warming. Here’s a rundown of the most common pollutants emitted by landfill sites.

Methane

Because waste is compressed and stored deep underground, there is very little oxygen present in sealed landfill sites. This can lead to the generation of methane, a leading greenhouse gas. In fact, methane is over 80 times more effective at trapping heat in the Earth’s atmosphere than carbon dioxide. As such, monitoring emissions of methane is imperative in order to bring global warming under control, especially at sources like landfill sites.

Carbon dioxide

CO2 is another pollutant found in abundance at landfills. Although methane might be more potent in the short term, carbon dioxide can persist in the environment for much longer periods of time. Whereas methane is normally gone inside a decade or slightly longer, CO2 can endure for hundreds or even thousands of years. This makes it a highly concerning by-product of landfill use and one which must be taken into account when targeting a net-zero future.

Heavy metals

Heavy metals like arsenic, cadmium, lead and mercury are valuable commodities which are present in many modern consumer products, from smartphones to computers to lightbulbs to batteries. But while they contribute much to our society, they’re also highly toxic when inhaled or ingested. If allowed to leach into the soil, groundwater or air, they could compromise the quality of those media and adversely affect human, plant and animal life in the surrounding ecosystems.

Polycyclic aromatic hydrocarbons (PAHs)

A class of chemicals that occur naturally in fossil fuels like gas, oil and coal and organic matter such as wood and tobacco, polycyclic aromatic hydrocarbons (PAHs) are produced during the combustion of those materials. If inhaled, PAHs are converted into metabolites in the human body and later excreted. However, they do not exit the body without leaving their mark. A known carcinogen, PAHs can contribute to various forms of cancer and eventually cause premature death in the exposed individual.