COVID-19 is overcrowding cemeteries and causing heavy metal pollution

The Omicron surge has triggered a devastatingly fast-paced wave of deaths across the United States as the COVID death toll passed the grim threshold of over 900,000 on February 4. Over the last two weeks, the number of deaths drastically increased in Brazil and India by 167 percent and 136 percent, respectively.

The coronavirus pandemic has claimed over 5.7 million lives worldwide. Funeral homes, mass burial grounds, and crematoriums remain overwhelmed and pushed beyond capacity. Last April, gravediggers in São Paulo had to exhume old graves in a cemetery and relocate corpses’ remains in a desperate attempt to bury thousands of daily COVID.

Researchers argue that cemeteries are one of the most neglected and insidious sources of metal contamination in the soil. As the COVID pandemic drags on, metal pollution in cemeteries and surrounding areas could reach staggeringly high levels—further aggravating the risk of groundwater contamination.

In the putrefaction stage of corpse decomposition, bodies release several liters of water as well as a vast range of heavy metals in a brownish-gray liquid called cemetery leachate.

Around 60 percent of cemetery leachate is composed of water. Another 30 to 40 percent are mineral salts. The remaining 10 percent consist of organic substances and various naturally-present metallic compounds such as calcium, chromium, iron, manganese, and lead. It takes up to three years for a buried body to generate cemetery leachate before it starts trickling into the soil.

Letícia Rocha Goncalves, a biologist at the São Paulo State University in Brazil, has researched the composition of the cemetery leachate and how it could potentially be a significant contaminant during the COVID-19 pandemic. After analyzing data from various scientific journals, government publications, and global environmental agencies, she found that the steep increase in COVID deaths has resulted in urban cemeteries becoming yet another severe threat to the environment and health of nearby communities. Her findings were published in Environmental Science and Pollution Research.

“As the demand for burials is far higher during the COVID pandemic, people need to be aware of the potential environmental damage,” she says to Popular Science. “We urgently need to implement health policies to mitigate this problem.”

Goncalves says corpses that undergo embalming procedures are one of the most major sources of metal contamination in cemeteries. During the embalming process, cemetery workers use formaldehyde, potassium nitrate, and chrome paint. As an embalmed body decomposes, those metals, including arsenic, mix with cemetery leachate and percolate deep into the soil. Medical devices, such as orthopedic implants, dental fillings, and pacemakers, could also contribute.

Bodies themselves aren’t the only concern. Coffins, which are made of different types of steel and wood that are treated with varnishes, release zinc, aluminum, and copper that could corrode and seep into soils via cemetery leachate.

Several variables such as a region’s climate, precipitation patterns, and daily temperatures play an important role in the accumulation, transmission, and corrosion of metals in the soil of cemeteries. Cemeteries located in regions that experience high temperatures and rainfall frequently are more likely to have higher levels of metal pollutants in the soil.