Not only the natural environment, but also micro-plastics penetrate into our food and drinking water. For example, an analysis of many common brands of bottled drinking water shows that 93% of the samples contain micro-plastics; last year at the European Gastroenterology Conference Another study reported the first discovery of microplastics in human feces.
If people around the world swallow these micro-plastics day in and day out, what impact will they have on their health?
Driven by findings such as this, the World Health Organization (WHO) decided to conduct a security review. Recently, based on the results of existing research, WHO released an analysis report on micro-plastics in drinking water, which is the first time that WHO has studied the potential human health risks associated with micro-plastics in the environment.
| References [1]
The WHO noted that microplastics have been detected in seawater, wastewater, fresh water, food, air and drinking water, including bottled water and tap water.
There are three main categories of potential hazards associated with microplastics:
The particle itself has physical hazards, including its size, surface area, shape and surface characteristics.
Chemical properties of the particles themselves and their adsorbates
Microbial effects of attachment and colonization on microplastics
However, due to the scarcity of micro-plastics related to drinking water and exposure data, WHO's expert group can only review nine studies on micro-plastics in drinking water, many of which are considered to be of low quality.
Overall, there is currently insufficient informat the human body, that is, “seems” not to threaten health.
Most of the existing research has focused on larger plastic particles rather than nanoparticles. The WHO noted that it is unlikely that the human body will absorb microplastics larger than 150 microns and that the absorption of smaller particles is also limited. Very small microplastic particles (including nanoparticles) may be absorbed and distributed in the human body, but the data is extremely limited. Animal experiments have shown that under the exposure of very high concentrations of microplastic particles, the animals will absorb due to the removal mechanism of the organism itself, but the test concentration far exceeds the concentration of microplastic particles in drinking water.
What is the concept of these particle sizes? According to this report, the minimum particle size of microplastics detected in drinking water is 1 micron, but it does not mean that there are no smaller particles, but is limited by existing detection methods. The particle sizes of the different studies reported were inconsistent and the data were limited. Some studies reported that most of the particles were below 20 microns, while others were considered to be within 150 microns. This is not covered by the above-mentioned “less likely to absorb” or “limited absorption”. As you can see, the evidence to explain the problem is very limited.
The impact of micro-plastic related chemicals and microbial pathogens on human health in drinking water is also very lacking in scientific research.ion to arrive at a definitive conclusion, but there is no reliable research showing that these micro-plastic particles in drinking water are significantly harmful to
This may seem reassuring for the time being, but it does not mean that we can breathe a sigh of relief. Paul Harvey, an environmental scientist at Macquary University in Australia, said that no data does not mean that there is no problem. David Green, chairman of the Environmental Group of the Society of Chemical Engineers, also believes that “the future may not be so optimistic as evidence builds up.” Concerns about the health effects of microplastics will continue until more reliable scientific support is available.
Dr. Maria Neira, WHO's Director of Public Health, also called for “we urgently need to go further (to conduct research) to understand the health effects of microplastics. We also need to curb the rising trend of global plastic pollution.”
The WHO also suggested that people should develop standard methods for detecting micro-plastic particles in water, and study the sources and specific conditions of micro-plastics in fresh water, as well as the effects of different micro-plastic treatment methods. At present, more than 90% of the microplastics can be removed from the wastewater by wastewater treatment, and the removal rate of the tertiary treatment (such as filtration) is the highest. In drinking water treatment, data on the removal of micro-plastics is still limited, but conventional treatments are known to remove particles smaller than 1 micron. More advanced techniques such as nanofiltration can remove particles > 0.001 microns, which are usually smaller than micro-particles. Plastics are also higher in concentration than microplastics.
The International Water Management Institute is also working with the United Nations Environment Programme to evaluate solutions for micro-plastics, including limiting the use of disposable plastic products and reducing micro-plastic additives in daily-use products such as toothpaste.
This report is only a starting point for research on microplastic health issues. In addition to the scientific discovery and development of micro-plastic processing technology, it is a small matter that we can do our best to use disposable plastic products and recycle them as much as possible.
Reference material
[1] Microplastics in drinking-water. Retrieved Aug 27, 2019, from https://www.who.int/zh/news-room/detail/22-08-2019-who-calls-for-more-research-into-microplastics-and-a-crackdown-on-plastic-pollution
[2] WHO calls for more research into microplastics and a crackdown on plastic pollution. Retrieved Aug 27, 2019, from https://www.who.int/news-room/detail/22-08-2019-who-calls-for-more-research-into-microplastics-and-a-crackdown-on-plastic-pollution
[3] The WHO Has No Idea if Microplastics in Our Water Are Harmful or Not. Retrieved Aug 27, 2019, from https://www.sciencealert.com/we-literally-have-no-idea-if-microplastics-in-our-water-is-bad-for-our-health
[4] expert reaction to WHO report on microplastics in drinking water. Retrieved Aug 27, 2019, from https://www.sciencemediacentre.org/expert-reaction-to-who-report-on-microplastics-in-drinking-water/
5] Microplastics Found in Human Stool. Retrieved Aug 27, 2019, from https://eos.org/articles/microplastics-found-in-human-stool
[6] Melanie Bergmann, et al., (2019). White and wonderful? Microplastics prevail in snow from the Alps to the Arctic. Science Advances, 10.1126/sciadv.aax1157
