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| Pine needles in Korea can now be used to gauge the level of heavy metal air pollutants in particular areas. Gettyimagesbank |
By Ko Dong-hwan
A new technology by the Ministry of Environment has allowed pine needles to be used as bioindicators to read the levels of air pollution caused by heavy metal particles.
The technology was developed from the idea that heavy metals in the air are absorbed by living tree leaves and accumulate inside them.
One of the main advantages of the technology is that it allows reading air pollutants in areas where there are no air quality monitoring stations nearby or where it is difficult to transport air quality reading devices, due to the conditions of the particular area.
The fact that pine trees in Korea are perennial also makes it convenient to use the technology with them. Pine needles were also chosen for this technology because the needles stay attached to pine tree branches for at least two years, giving them ample time to accumulate and store up heavy metals from the air, if there are any.
Developed by the National Institute of Environmental Research (NIER) under the ministry, the technology requires a sample of pine needles from trees that are at least a year old and minimum three meters tall in areas suspected of air pollution. The collected pine needles need to be shredded, while being kept at an ultralow temperature, and then go through a homogenization process.
After freeze-drying the samples, they go through a preprocessing treatment. After that, the samples should be examined using devices such as an ICPAES (inductively coupled plasma atomic emission spectrometer) and a GCMS (gas chromatography mass spectrometer) to measure the potential pollutants in them, such as lead, cadmium, chromium and polycyclic aromatic hydrocarbons (PAHs).
The NIER said that the technology is valuable because it provides a new environmental index, using a plant that can be found easily. The agency plans to test the technology in the field starting next year.
"Not only via pine needles, but we will develop more bioindicators to utilize them more rigorously in detecting pollutants in the air, water and land," the NIER's environmental resources research department chief, Yoo Myeong-soo, said.
Korea's Clean Air Conservation Act defines 64 air pollutants, ranging from gaseous contaminants to particulate matters. They include 10 different types of heavy metal air pollutants, 16 PAHs and 16 volatile organic compounds (VOCs). The laws state that air containing more than 0.5 micrograms per cubic meter of lead per year on average, or more than 5 micrograms per cubic meter of benzene (classified as a VOC) per year on average, is considered polluted.
