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Critical assessments needed in a world full of fear-mongering fake news

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Radiation danger from Mineral Sands at Pulmoddai:

A recent media report has said sand (from Pulmudai) emits more than 500 units of radiation per minute, more than the current level of radiation after the Fukushima radiation leak in Japan.

This sort of material is misleading and should NOT be publicized without due analysis. When a report does not give a source, does not specify the units, and refers to, say Chernobyl or Fukushima’s current level of radiation without telling us what that it is, and if that is dangerous, you can clearly see fear-mongering.

We live in a technological world where a tiny minority of people have the needed training to evaluate the information. Even with due training, we need is critical thinking and restraint. Even scientists loose their critical capacity when they move out of their narrow specialty and look at other news that can be psychologically fearful. Then they often hide under a false “precautionary principle” and take the wrong actions.

The news clip says “500 units of radiation” What are these units? Are they measuring alpha-particles, gamma rays, or beta decay?Different radiations have different thresholds.

Just as with chemical toxins, even with radiation, there are thresholds. If the active agent is present at levels below the thresholds for chronic toxicity, there is no problem. It is because people don’t understand thresholds, or do not have time for looking at thresholds, that they went about banning glyphosate, and similarly DDT was banned from domestic use against mosquitoes. With chemical toxins people fail to distinguish between acute toxicity and chronic toxicity and rush to act. It is the gut reaction of urban people who do not know about snakes to attack even a “gaerandiya” (non-poisonous snake that hunts mice) and kill it thinking it may be a cobra – that is the wrong application of the so-called precautionary principle.

So, even with radiation, the first question to ask is, what are the thresholds (minimal daily admissible amounts) on radiation exposure set by the WHO. When radiation is absorbed in living matter, a biological effect may be observed. However, equal absorbed doses will not necessarily produce equal biological effects. The effect depends on the type of radiation (e.g., alpha, beta, gamma, etc) and the tissue or organ receiving the radiation. For example, 1 Gy of alpha radiation is more harmful to tissue than 1 Gy of beta radiation. To simplify matters, a Sievert is used as the measure of radiation damage.

The Sievert (Sv) is the unit of effective dose that takes into account the type of radiation and sensitivity of tissues and organs. It is a way to measure ionizing radiation in terms of the potential for causing harm. A thousandth of a Sievert is a milli-Sievert (mSv). The dose threshold for acute radiation syndrome is about 1 Sv (1000 mSv).

Regions at higher altitudes receive more cosmic radiation. According to a study by Health Canada, the annual effective dose of radiation from cosmic rays in Vancouver, British Columbia, which is at sea level, is about 0.30 mSv. This compares to the top of Mount Lorne, Yukon, where at 2,000 m, a person would receive an annual dose of about 0.84 mSv. Air travel also increases exposure to more cosmic radiation, for a further average dose of 0.01 mSv per Canadian per year. Similar effects are applicable for other countries as well.
One Sievert of radiation exposure for an year increases the likelihood of developing cancer sometime in your lifetime by 5%. But not that 5% of people will get cancer, but that one has the chance of developing cancer increased by 5% – most people won’t get cancer. People living in the topics already have a higher natural chance because they are exposed to cosmic radiation anyway. Strangely enough, there is also the growing evidence and argument from experts in radiology, that long-term exposure to low-levels of radiation may actually be beneficial to your health (but I am not sure if the data are at all significant).

Nevertheless we note that people living in areas like Beruwala coast get exposure to Monozite sands which are radioactive but we have heard of no increase in their cancer levels.I think the people living in the Beruwala coast, or in Puhlmotte (Pulmudai) get a natural exposure of about 10-15 mSv annually. The monozite sands contain thorium, Another example is the case of residents of Ramsar in Iran, with a background radiation of 250 mSv per year, have lower cancer rates than the world average. An astronaut in the space station gets about 150 mSv per annum.
The news report mentions Fukushima. You have to spend a whole year within 20km of the Fukushima plant to be exposed to 20 mSv of radiation. The Wikipedia article gives the following statement. Its contents are largely correct when judged against other reports.
” 180,592 people in the general population were screened in March 2011 for radiation exposure and no case was found which affects health.[22] Thirty workers conducting operations at the plant had exposure levels greater than 100 mSv. [23] It is believed that the health effects of the radioactivity release are primarily psychological rather than physical effects. Even in the most severely affected areas, radiation doses never reached more than a quarter of the radiation dose linked to an increase in cancer risk (25 mSv whereas 100 mSv has been linked to an increase in cancer rates among victims at Hiroshima and Nagasaki).[6][24] …In 2013 (two years after the incident), the World Health Organization indicated that the residents of the area who were evacuated were exposed to little radiation that radiation induced health impacts are likely to be below detectable levels.[31]”

The effect of cosmic radiation that is ever present everywhere is more dangerous than the effect of the Fukushima accident which is simply dramatic, fearful and news worthy but in the end not so dangerous as claimed.

So, given a report where they don’t even specify the units of measurement, or the type of radiation, the report should be regarded as false until proven valid, and ONLY the relevant authorities should act.

 

Chandre Dharmawardana

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