Reduction of Dangerous Water Pollutants through Tea Brewing

A recent study conducted by scientists at Northwestern University in the United States shows that brewing tea can effectively purify dangerous pollutants in water, including heavy metals like lead and cadmium. The research team concluded that tea eliminates these metals by forming a chemical bond with the charged atoms in the water. Benjamin Schindel, the lead author of the study, told the British newspaper The Guardian that a cup of black tea brewed for five minutes contains 15% less concentration of lead ions present in the water. Although the research team did not investigate the potential health implications of this reduction in heavy metals in water, Schindel noted that it could potentially reduce diseases related to heavy metal consumption. Previous studies have also indicated that individuals who drink tea may be at a lower risk of stroke, dementia, and even death. Schindel and his colleagues brewed tea with several types of water containing specific concentrations of heavy metal ions and then compared the concentration of these ions after various brewing periods with solutions without tea. They then focused on lead and found that longer brewing times of black tea and higher water temperatures were associated with a greater reduction in lead ion concentration. Additionally, the research group found that ground tea had a greater impact than whole tea leaves. The research team also discovered that black, green, and white teas reduced lead ion concentrations in water more than chamomile, rooibos, and oolong teas. The study also showed that the materials used in tea bags are important for reducing lead ions in tea. Cellulose bags reduced lead ion concentrations, while cotton or nylon bags did not. Global statistics indicate that tea is the second most consumed beverage in the world after water, with 5.5 million tons consumed annually. In Iran, Sadegh Hosseini, the director of the Tea Factories Syndicate in the northern country, recently announced that 60 to 70 thousand tons of tea are consumed annually.