The article is from the public number: I am a scientist iScientist (ID: IamaScientist) , author: Zhu Ye Hua, from the title figure: Figure worm creativity.

In 1956, the Minamata Bay area in Japan was shrouded in a terrible condition—patients twitched, deformed their hands and feet, bent over their backs, and even died. This is the shocking “Minamata Disease Incident” in history.

Minamata Disease | Photograph by Eugene Smith

Minamata disease is a consequence of heavy metal (mercury) pollution. And heavy metal pollution is one of the greatest threats to human health and the ecological environment, and it still cannot be underestimated. Due to unplanned industrialization and urbanization, the concentration of heavy metals in the environment is increasing at an alarming rate. The long-term presence of toxic heavy metals in the atmosphere, water and sediments and their bioaccumulation in the food chain have brought to all organisms A serious disaster.

Cadmium, mercury, and lead are among the 10 chemicals that have caused major public health concern and are released by the World Health Organization. These metal elements are systemic toxicants and pose a great threat to people’s health. Even low levels of exposure can cause damage to multiple organs.

This kind of super “killing power” keeps heavy metals in the spotlight. Over the years, the topic of excessive levels of heavy metals in cadmium-containing rice and baby foods has always stirred people’s tight nerves.

Heavy metals pollution

Ancient Roman civilization is an important part of the history of human civilization. Some historians believe that it is one of the main sources of Western civilization. But the highly developed ancient Roman civilization not only brought glorious achievements, but also hidden silent pollution.

Some studies have found that Lead pollution from the Roman Empire fell on Greenland and was preserved in the ice. In 2018, Oxford University archaeologists collaborated with ice core research experts to measure a Greenland ice core with a cross section of about 400 meters.Lead concentrations in several places were plotted for lead pollution in the Roman era, and an exceptionally detailed timeline of lead pollution in Rome during 1900 was obtained. The tested ice core represents the frozen layer [1] from 1100 BC to 800 AD.

Lead pollution from the Roman Empire is preserved in the ice of Greenland | Pixabay

It is inconclusive whether the demise of ancient Rome was related to severe heavy metal pollution, but in the 20th century after the millennium, two heavy metal poisoning incidents that shocked the world occurred in Japan, and the resulting diseases are well known to the world, Minamata disease and painful disease in Japan .

The Minamata disease incident in Japan from 1953 to 1956 was the result of mercury poisoning. Mercury-containing wastewater is consumed by fish and converted into methylmercury in the fish. Residents near Minamata Town will consume fish that is rich in methylmercury and absorbed by the human body. It is not easy to decompose in the body, it is slow to excrete and it is highly toxic. Methylmercury is a high neurotoxic agent, which accumulates in the brain. When the methylmercury accumulates in the human body to a certain concentration, a series of symptoms mentioned at the beginning of the article will occur.

Shintokawa’s bone pain from 1955 to 1963 was the result of cadmium poisoning. The zinc smelting plant discharges cadmium-containing wastewater into the Shendongchuan River. Farmers have long-term diverted river water to irrigate the rice. Coastal residents drink cadmium-containing water. The edible rice also contains cadmium. After a certain concentration is accumulated in the body, painful diseases occur. Painfulness can cause joint pain, skeletal deformity, pain and suicide.

In 2011, a “cadmium rice killer” by New Century Weekly caught the attention of the whole country. In the “two sessions” of the year, cadmium rice also became a hot topic. This “cadmium rice incident” can be said to be a node, letting the government and the public once again see the problem of heavy metal pollution in China. Many experts have confirmed that as early as the 1960s, the village of Siping, Xingping Town, Yangshuo County, Guangxi reported heavy metal cadmium pollution, and the cadmium content in the rice produced had also seriously exceeded the standard. Locals have long consumed rice with excessive cadmium.

Yunnan ’s chromium slag pollution is one of the most serious pollution incidents in 2011. A 5,000 tons of highly toxic chromium slag is published in the Yunnan Information Newspaper. In front of the readers, the local government apologized, dealt with the pollution promptly, and arrested the polluters. The relevant departments of the central government reported that it caused strong repercussions throughout the country.

Rice grown on cadmium-contaminated land will also exceed standards | Caixin.com


Heaven enters the underground sea, heavy metal pollution is everywhere

Heavy metals in the environment come from all sources, including the genesis of the earth, industry, agriculture, pharmaceuticals, domestic wastewater and atmospheric sources.

Environmental pollution is prominent in point source areas such as mining, foundries and smelters, and other metal industry operations. Although heavy metals are natural elements commonly found in the earth’s crust, most pollution is caused by human activities, such as mining and smelting operations, industrial production and use, and household or agricultural use of metals or metal-containing compounds.

Heavy metal pollution of surface water is a global environmental problem .

A new study analyzes five continents from 1970 to 2017. (Africa, Asia, Europe, North and South America) [2] of trends, health risks and sources of heavy metal dissolution. Overall, cadmium, chromium, nickel, manganese, and iron in the water system showed an upward trend, and lead and zinc showed a downward trend. The average dissolved concentrations of most heavy metals are highest in Asia and lowest in Europe.

From 1970 to 2017, miningAnd manufacturing has been considered a key source of metal pollution. However, there are significant differences in the sources of heavy metals across continents. Africa is dominated by waste emissions and rock weathering; Asia and South America are dominated by mining and manufacturing and rock weathering; North America is dominated by the use of fertilizers and pesticides; Europe is Mining and manufacturing, waste discharge and rock weathering dominate.

Heavy metal pollution of surface water is a global environmental problem | Pixabay

China faces huge challenges in protecting soil from rapid industrialization and urbanization.

According to China’s soil environmental quality standards, recent national surveys show that 16% of soil samples and 19% of agricultural soil samples are contaminated, mainly heavy metals and metals. The concentration of certain heavy metals in Chinese soil appears to be increasing at a faster rate. In some areas, especially in southern China, due to the increased input of pollutants and the acidity of the soil, crop species are prone to accumulate heavy metals, which has led to the widespread occurrence of pollutants in food crops.

Yunnan Qujing Chrome Slag Yard | Caixin.com

In 2016, UNICEF published a report (Danger in the air) “) ​​ claims that air pollution will be a deadly killer of children’s health in this century, and outdoor air in areas where about 300 million children live will be severely polluted. Such air can cause severe damage to children’s bodies, including damage to their developing brains. In air pollution, heavy metal particles are one of the most important pollutants.


Heavy Metal Tracking

Heavy metal waste comes from a wide range of industries, including mining, metallurgy, electroplating, steel, chemical, machinery manufacturing, electronics and instrumentation. Heavy metals cannot be biodegraded into harmless substances, which can accumulate in the organism. Some heavy metals can be converted into more toxic organic compounds under the action of microorganisms. In addition, heavy metals can have toxic effects at very low concentrations Generally, the toxicity of heavy metals is in the range of 1.0-10 mg / L. Therefore, it is necessary to strictly control the pollution discharge of heavy metal wastewater, which is an important means and measure to contain pollutants.

Guangxi Daxin Lead-Zinc Mine has caused serious environmental hazards for more than 40 years due to inadequate wastewater pollutant treatment | Tuworm Creative

For soil and water bodies that have been contaminated with heavy metals, scientists are also actively adopting various technical measures to reduce the damage of heavy metals to the environment and organisms.

If you want to remove heavy metals from the environment, you must first find the traces of heavy metals. Biological monitoring is one of the effective methods. Scientists have known for a long time that when bees fall on flowers and leaves, they will absorb a small amount of metal elements attached to them. ) . Recently, lead isotope analysis of honey has demonstrated its usefulness as a biological monitor for lead source analysis applications.Effectiveness .

Scientists collect honey directly from beehives in six geographic regions of Canada to investigate potential contaminants from different subdivisions of urban, industrial, residential and agricultural sectors. Bees bring these metals back to the hive, where traces of metal are mixed into the honey. By analyzing the relative presence of different lead isotopes in honey, Vancouver scientists have been able to track the source of lead (and other metals) [4] . Scientists in France, Belgium and Italy are now looking for the same method to measure pollutants in honey in major European cities.

Some scientists have combined the analysis of honey and salmon to show how natural and industrial sources of lead are distributed throughout the environment. [5]

Bees can help monitor urban pollution | phys.org

Brown trout is a native fish in rivers in northern Spain. It is the main fish species in these rivers and is widely distributed in all freshwater ecosystems in the area, including those that may be contaminated by heavy metals. Researchers conducted copper, lead and cadmium concentrations in abiotic compartments (water and sediment) and brown trout from three rivers in northern Spain analysis. It was found that there was a significant correlation between lead content and lead concentration in trout liver sediments. Juvenile trout has also proven to be a useful biological monitor for copper and lead contamination. [6] .

Bird eggs, snakes, and shellfish are all used by scientists to monitor the presence of heavy metal pollutants in the environment. As monitoring technology continues to be recommended, more animals and even plants will be used for heavy metal pollution. Monitoring.

Heavy metal pollution is not irreversible, but there are practical problems that are difficult to manage. Therefore, the prevention of soil heavy metal pollution should focus on “prevention”. If the “prevention” work is not done well, a worse situation will occur, that is, the rate of pollution is faster than the speed of treatment. For China, heavy metal pollution is not optimistic due to the industrial development of the previous decades. Children’s blood lead incidents and cadmium incidents have sounded alarm bells for us. Only by paying close attention can we avoid more heavy metal pollution disasters.

References:

[1] Joseph R. McConnell, Andrew I. Wilson, Andreas Stohl, et al. Lead pollution recorded in Greenland ice indicates European emissions tracked plagues, wars, and imperial expansion during antiquity [J]. PNAS, 2018, https://doi.org/10.1073/pnas.1721818115.

[2] Li Youzhi; Zhou Qiaoqiao; Ren Bo; et al. Trends and Health Risks of Dissolved Heavy Metal Pollution in Global River and Lake Water from 1970 to 2017 [J] . Rev Environ Contam Toxicol; 251: 1-24, 2020.

[3] Zhao Fang-Jie, Ma Yibing, Zhu Yong-Guan, et al. Soil Contamination in China: Current Status and Mitigation Strategies [J]. ENVIRONMENTAL SCIENCE & TECHNOLOGY , DOI: 10.1021/ es5047099.

[4] Kate E. Smith, Dominique Weis, Marghaleray Amini, Alyssa E. Shiel, Vivian W.-M. Lai & Kathy Gordon. Honey as a biomonitor for a changing world [J]. Nature Sustainability, volume 2, pages 223–232 (2019).

[5] https://phys.org/news/2019-08-scientists-honey-wild-salmon-industrial.html.

[6] ARLinde, S. Sánchez-Galán, JIIzquierdo, et al. Brown Trout as Biomonitor of Heavy Metal Pollution: Effect of Age on the Reliability of the Assessment [ J]. Ecotoxicology and Environmental Safety, Volume 40, Issues 1–2, May 1998, Pages 120-125.

The article is from the public number: I am a scientist iScientist (ID: IamaScientist) , author : Zhu Yehua (a young doctor from Tsinghua University, who likes to answer children’s wild questions).