reporter2
01-09-21, 11:38
Dispelling the fear of 'radioactive sushi'
The primary anxiety is that the entry of radioactive substances into the food chain is going to trigger a spurt of cancers.
Wong Seng Weng
Dr Wong Seng Weng is the medical director and consultant medical oncologist at The Cancer Centre.
Aug 31, 2021
SINGAPORE - If you worry that radioactive sushi may end up on your dining table and bump up your risk of cancer, you are not alone.
After news broke in April of Japan's plan to release treated radioactive waste water from the damaged Fukushima nuclear plant into the sea in a few years' time, howls of protest could be heard. These came not only from countries in the region, but also segments of the Japanese population.
The primary anxiety, of course, is that the entry of radioactive substances into the food chain is going to trigger a spurt of cancers in the affected populations.
Radiation and cancer have always had a curious relationship.
That radiation can cause cancer is no longer in dispute.
The International Agency for Research on Cancer - which is under the World Health Organization - has placed radiation in the highest risk category in its classification of cancer-causing agents.
However, cause and effect is not the only relationship between radiation and cancer. As a cancer doctor, I use radiation to diagnose, treat and assess the progress of therapy of cancers every day. As the Chinese saying goes: Water can float a boat, just as it can capsize it.
Adding to the confusion over the threat posed by radiation to our health are controversies over the radiation emitted by common devices, chiefly cell phones and microwave ovens.
To dispel the fog of confusion, the easiest ghost to lay to rest would be the risk of cancer from these everyday lifestyle devices such as mobile phones and microwaves.
The electromagnetic radiation emitted from such devices is of the low-frequency type that is highly unlikely to trigger cancer formation. In medical parlance, this is non-ionising radiation.
The frequency of such radiation waves is too low to damage the DNA structure of the genes of the body's cells. DNA damage is the precursor to genetic mutations that set off the transformation of well-behaved normal cells into out-of-control cancer cells.
Research papers flagging the possible increased risk of a form of brain cancer (malignant glioma) in people who frequently use mobile phones are often contradicted by findings from other papers.
While the jury is out over the cancer risk associated with mobile phone radiation, the danger, if any, is likely to be minuscule.
Radiation emitted by medical equipment such as radiotherapy machines and computerised tomography scanners, on the other hand, is a different animal.
Such ionising radiation is capable of causing DNA damage in cells, potentially leading to cancer-related genetic mutations.
Doctors are generally not cavalier when it comes to recommending medical investigations or treatments that involve the use of radiation. The potential benefits and risks are carefully weighed before recommendations are given.
The risk of radiation-induced cancers is also why I check on patients who have undergone radiotherapy for cancer, even if they are deemed to have been permanently cured.
There is always a remote chance that the radiation given may have wiped out one cancer, just to trigger another one down the road.
So, what of the radiation from isotopes in the defunct Fukushima nuclear plant? Dangerous or not dangerous? Ionising or non-ionising?
Yes, ionising. A modern rejoinder of the Chinese saying on boat and water may be: Radioactive water can do more than just float or capsize a boat.
The waste water must undergo treatment to remove radioactive isotopes as much as possible and to dilute the water before discharge.
While diluting the waste water does not get rid of radioisotopes per se, it may reduce the intensity of exposure to a level close to that of background environmental radiation.
The threat from any radiation-related incident must be viewed in context. We are already exposed to ionising radiation from the environment every day.
Where does this background environmental ionising radiation come from? Two of the most prominent "natural" sources of ionising radiation are radon gas released from the planet's crust and cosmic radiation that penetrates the ozone layer of the atmosphere.
In short, it is impossible to totally avoid ionising radiation.
A few friends who are fans of salmon sushi have half-jokingly said to me that they will have to forsake this love of theirs.
Actually, salmon sashimi and sushi are probably the safest options in the plethora of raw fish choices, as raw salmon does not appear in authentic Japanese cuisine.
The Japanese traditionally believe that the flesh of the Pacific salmon carries parasites and eat only the roe raw. The appearance of raw salmon - mostly farmed Atlantic salmon - in modern Japanese cuisine is the result of a successful marketing stunt by Norwegian salmon sellers.
So, go ahead. Have your salmon sushi.
The primary anxiety is that the entry of radioactive substances into the food chain is going to trigger a spurt of cancers.
Wong Seng Weng
Dr Wong Seng Weng is the medical director and consultant medical oncologist at The Cancer Centre.
Aug 31, 2021
SINGAPORE - If you worry that radioactive sushi may end up on your dining table and bump up your risk of cancer, you are not alone.
After news broke in April of Japan's plan to release treated radioactive waste water from the damaged Fukushima nuclear plant into the sea in a few years' time, howls of protest could be heard. These came not only from countries in the region, but also segments of the Japanese population.
The primary anxiety, of course, is that the entry of radioactive substances into the food chain is going to trigger a spurt of cancers in the affected populations.
Radiation and cancer have always had a curious relationship.
That radiation can cause cancer is no longer in dispute.
The International Agency for Research on Cancer - which is under the World Health Organization - has placed radiation in the highest risk category in its classification of cancer-causing agents.
However, cause and effect is not the only relationship between radiation and cancer. As a cancer doctor, I use radiation to diagnose, treat and assess the progress of therapy of cancers every day. As the Chinese saying goes: Water can float a boat, just as it can capsize it.
Adding to the confusion over the threat posed by radiation to our health are controversies over the radiation emitted by common devices, chiefly cell phones and microwave ovens.
To dispel the fog of confusion, the easiest ghost to lay to rest would be the risk of cancer from these everyday lifestyle devices such as mobile phones and microwaves.
The electromagnetic radiation emitted from such devices is of the low-frequency type that is highly unlikely to trigger cancer formation. In medical parlance, this is non-ionising radiation.
The frequency of such radiation waves is too low to damage the DNA structure of the genes of the body's cells. DNA damage is the precursor to genetic mutations that set off the transformation of well-behaved normal cells into out-of-control cancer cells.
Research papers flagging the possible increased risk of a form of brain cancer (malignant glioma) in people who frequently use mobile phones are often contradicted by findings from other papers.
While the jury is out over the cancer risk associated with mobile phone radiation, the danger, if any, is likely to be minuscule.
Radiation emitted by medical equipment such as radiotherapy machines and computerised tomography scanners, on the other hand, is a different animal.
Such ionising radiation is capable of causing DNA damage in cells, potentially leading to cancer-related genetic mutations.
Doctors are generally not cavalier when it comes to recommending medical investigations or treatments that involve the use of radiation. The potential benefits and risks are carefully weighed before recommendations are given.
The risk of radiation-induced cancers is also why I check on patients who have undergone radiotherapy for cancer, even if they are deemed to have been permanently cured.
There is always a remote chance that the radiation given may have wiped out one cancer, just to trigger another one down the road.
So, what of the radiation from isotopes in the defunct Fukushima nuclear plant? Dangerous or not dangerous? Ionising or non-ionising?
Yes, ionising. A modern rejoinder of the Chinese saying on boat and water may be: Radioactive water can do more than just float or capsize a boat.
The waste water must undergo treatment to remove radioactive isotopes as much as possible and to dilute the water before discharge.
While diluting the waste water does not get rid of radioisotopes per se, it may reduce the intensity of exposure to a level close to that of background environmental radiation.
The threat from any radiation-related incident must be viewed in context. We are already exposed to ionising radiation from the environment every day.
Where does this background environmental ionising radiation come from? Two of the most prominent "natural" sources of ionising radiation are radon gas released from the planet's crust and cosmic radiation that penetrates the ozone layer of the atmosphere.
In short, it is impossible to totally avoid ionising radiation.
A few friends who are fans of salmon sushi have half-jokingly said to me that they will have to forsake this love of theirs.
Actually, salmon sashimi and sushi are probably the safest options in the plethora of raw fish choices, as raw salmon does not appear in authentic Japanese cuisine.
The Japanese traditionally believe that the flesh of the Pacific salmon carries parasites and eat only the roe raw. The appearance of raw salmon - mostly farmed Atlantic salmon - in modern Japanese cuisine is the result of a successful marketing stunt by Norwegian salmon sellers.
So, go ahead. Have your salmon sushi.