Open-air e-waste dismantling sites should be banned, say researchers, as new evidence shows they pollute the atmosphere and could have a significant effect on human health.
Each year, some 20 million tons of e-waste - defunct PCs, televisions, mobile phones and the like - is generated worldwide. And researchers writing in Environmental Research Letters say they have now linked the stuff to inflammation and oxidative stress – precursors to several serious diseases.
"Both inflammatory response and oxidative stress may lead to DNA damage, which could induce oncogenesis, or even cancer," says co-author Dr Fangxing Yang of Zhejiang University. "Of course, inflammatory response and oxidative stress are also associated with other diseases, such as cardiovascular diseases."
The team took air samples from one of the largest e-waste dismantling areas in China and examined their effects on human lung epithelial cells. The Taizhou center in Zhejiang province involves more than 60,000 people and dismantles more than two million tons of e-waste each year.
The samples included persistent organic pollutants and heavy metals, which can easily accumulate in the human body.
And after exposing the cultured lung cells to the organic-soluble and water-soluble constituents of the samples, the researchers tested for the level of Interleukin-8 (IL-8), a key mediator of inflammatory response, and Reactive Oxygen Species (ROS) - chemically reactive molecules that can cause extensive damage in excess.
They were also tested for the expression of the p53 gene – a tumour suppressor gene that produces a protein to help counteract cell damage. If there is evidence of this gene being expressed it can be seen as an indication that cell damage is taking place.
The results showed that the samples of pollutants caused significant increases in both IL-8 and ROS levels – indicators of an inflammatory response and oxidative stress respectively. Significant increases were also observed in the levels of the p53 protein with the risk of organic-soluble pollutants being much higher than water-soluble pollutants.
"From these results it is clear that the 'open' dismantlement of e-waste must be forbidden with more primitive techniques improved. As the results show potential adverse effects on human health, workers at these sites must also be given proper protection," warns Wang.
"Furthermore, one must consider the initial manufacturing process of electrical goods and look to utilise more environmentally and human friendly materials in their production."