“Human health and ecological toxicity potentials due to heavy metal content in waste electronic devices with flat panel displays”
Journal of Hazardous Materials
What were the system boundaries chosen by the authors of the study?
What life cycle stage had the greatest impact?
This study focused specifically on CRTs and LCDs, as used for computer desktop displays. These devices are known for their heavy metal components which eventually turn into gas and are deposited into the water. Apparently what turns into ash then leaches into the water, so inevitably all of these toxins get into our water system.
The US-centric metrics used by the U.S. EPA in this case began in 1995 and is used to measure data in this study. The author notes that an average was taken based on location but, however, did not include occupational exposure in the data.
The potential human health toxicity and exotoxicity were determined by something the author defined as pathway and impact models averaging “toxicity potentials, sales volume over time, product weights, lifetimes of each device, and the fraction of devices landfilled and incinerated.” These devices totaled less than 1% of landfill/incinerated waste set at .82% in 2006 and .85% in 2005.
I was disturbed to learn that LCD screens contain arsenic (improved clarity of the screen) and mercury is found in backlit LCD models. A conductive film in LCDs can cause lung disease and/or cancer. If these products continue to be made with heavy metals and continue to be incinerated or placed in landfills, they will continue to poison the air and water.
According to the study, cancer potentials from laptops and LCD monitors will most likely increase significantly between 2009-2011. Furthermore, plasma TVs will become a significant part of the equation in 2021. This is all very scary stuff. It was difficult for me to decipher from this study the greatest impact other than I assume “end of life” when materials are disposed of and the toxic heavy metals seep into our water supply and into the air.