Good news for tea lovers: brewing a daily cup of tea might also be purifying the water, removing toxic heavy metals like lead and cadmium. Researchers at Northwestern University have discovered that tea leaves naturally adsorb these contaminants, effectively filtering them out of drinking water.
The study found that the type of tea bag used is crucial in determining how well it removes heavy metals from water. Cellulose bags were found to work best and didn’t release microplastics. Finely ground tea leaves also adsorbed more metal ions than whole leaves due to their increased surface area.
Steeping time played a significant role in the removal of contaminants, with longer steeping times resulting in higher levels of remediated lead. The researchers estimate that brewing tea can remove around 15% of lead from drinking water, even at high concentrations.
While this study doesn’t solve water crises, it provides valuable new information on the potential benefits of tea consumption for public health research. Drinking an extra cup of tea per day may help explain why populations with higher tea consumption rates have lower incidence rates of heart disease and stroke.
The researchers’ findings highlight the unrecognized potential for tea leaves as a natural filter material. With no need to do anything extra, just steeping tea leaves in water can remove heavy metals, making it a simple and effective way to purify drinking water.
Source: https://phys.org/news/2025-02-brewing-tea-toxic-heavy-metals.html