Accidental exposures in medical

 Accidental exposures in medical applications of radiation uses of radiation, particularly in radiotherapy, can be of concern, w.r.t patient safety, and occupational exposure considerations. New technologies may bring in improvement to the therapy. However, these technologies involve increase in the complexities of the systems, which in turn may cause new types of human error and problems with the equipment.

It is very important that any errors leading to or likely to lead (near misses) to serious consequences need to be investigated in time, and in detail. Dissemination of the information on these errors is crucial in preventing re-occurrence. Lessons learnt from accidental exposures form an invaluable resource for revealing vulnerable aspects of the practice of radiotherapy. For details refer: ICRP 112.

Radon at home

Exposure to radon has been a major health hazard in uranium mines. Radiological safety aspects of the mine workers are adequately addressed in ICRP/IAEA/WHO documents. The issues are discussed in detail in the reference book on Radiological Protection and Safety - A Practitioner’s Guide.

Radon is also found airborne in homes, particularly in dwellings of cold countries, like United States and Canada where the air in the dwellings and work areas is recirculated.

Radon comes from the radioactive decay of natural of uranium/radium present in trace quantities in bricks, soil, rock, and water. Being gaseous, it gets into the air you breathe. Basement areas are more radon prone due to exhalation of radon from the floor and walls. Radon typically moves up through the basement/ground to the air above and into your living areas through cracks and other cavities in the foundation. There is a guide “Home Buyers and Sellers Guide to Radon” by US EPA (www.epa.gov) which covers all the radon related issues.  

What is radon (Rn-222)?

 Radon-222 is a gaseous radioactive, short-lived (half-life is 3.82d), inert gas produced by the alpha decay of radium-226 in the naturally occurring uranium-238 series. Radon is ubiquitous. 

Uranium and thorium are natural radioactive elements present in the earth and rocks in very small amounts. Hence, building materials such as sand, bricks and cement also contain some amount of uranium, thorium, radium-226 or radium 224. Since they are present in the earth, the water-soluble elements present, such as uranium and radium in the decay series, get into water resources and land mass. The gaseous radionuclides radon and thoron seep out of soil and get mixed with the atmospheric air.  

Thus, we get exposed to these gaseous radionuclides in dwellings as well as outside the dwellings. They contribute maximum to the radiation dose received by the world population by inhalation of the air contaminated with these radionuclides. The concentration of these radionuclides varies from place to place, dwelling to dwelling depending on the ventilation/air supply available for dilution and dispersion, and the concentration uranium and thorium in the materials. In cold countries, the concentration of radon in dwelling is likely to be of concern, since the dwellings are closed most of the time, and recirculation of the indoor air facilitates build-up of radon and its daughter products, thus create potential inhalation hazard.  

Ignorant members of public - About ionizing radiation

Let us frankly expose the TRUTH – Common man (person) including illiterate, semi-illiterate, and so-called literate or educated, hardly know anything about ionizing radiation, its benefits, and harmful effects. They only know that radiation is dangerous, so many thousands have died in the explosions of the atom bombs in Japan; the exposed person will lose hair and become impotent, etc etc. How we are going to explain all the benefits we are talking about to such a large percentage, maybe more than 90% of the population who are lacking an understanding of elementary radiation physics, mathematics, biology and medicine?

Communication is the key. All the practitioners of radiation and radiological protection, facility operators, and the government authorities should focus on ways and means to create awareness amongst the people about radiation: benefits of low-level exposures; medical uses in health-care; industry and food preservation; health effects at high levels of exposures, and how safely the radioactive waste is managed by well-informed experts. We should use mass media communication systems and school/college syllabus to the maximum possible extent. Desist from use of words, like probability, ALARA, risk analysis, etc when communicating with members of the public.

Integrated risk assessment – radiation and chemicals

Occupational workers work in an environment where there are mixed pollutants, some of them are cancer-causing and some may cause non-cancer diseases. For worker’s overall safety considerations, it may become necessary to assess health risks from individual pollutants, as well as combined risk from all the pollutants existing in the work environment. The pollutants may include chemicals, radiation, physical pollutants, etc.

Health effects of radiation or chemicals are classified as acute or chronic. Acute affects results from a single exposure to a high radiation dose rate or exposure to a high concentration of a chemical. The effect, deterministic in nature sets in rapidly and could be mild to severe. The dosage of chemicals or radiation plays a significant role in the level of severity of the effect. Chronic effects develop over a long period of exposure to a low concentration of chemical or low dose rate of radiation. The effect may remain invisible for a relatively long period, called the latent period. Carcinogenicity is included in chronic effects, which are stochastic in nature.

 For a given end-point, say cancer, the risk from the exposure/intake may be added to get an integrated risk, which may be expressed in terms of the risk equivalent radiation dose. As of now, ICRP assumes a total lifetime stochastic risk of 0.01 per Sievert of radiation dose received as tolerable. This is in the absence of ALARA.

An integrated risk assessment system needs to be in place to have an overall risk perspective for the benefit of policymakers and decision-makers to try to achieve risk reduction of the workers in totality – from radiation as well as chemicals. Thus, the total detriments will have different components. Once the risk from exposure to all the pollutants is quantified for a given end-point by some acceptable methodology, it can be expressed in terms of Risk Equivalent Radiation Dose (RERD).

Dose reductions for radiological safety in occupational scenarios can consider the risk of both the radiation and possible presence of chemical pollutant in the work environment. Similarly, environmental safety should take into account the ambient levels of chemical pollutants and the corresponding risk to the members of the public. 

Additional small contributions to the environmental pollution by the discharges from nuclear industry cause negligible risk as compared to the multiple chemicals risks, as seen by the calculated RERD values.

[More details, references in Harmonization of Risk Management Approaches-Radiation and Chemical Exposures, Pushparaja, and P. Srinivasan, Proc. IRPA 11, Madrid, Spain, 2011].

At the end of 2018 - good news to curb CO2 emissions

It is well know that powders like finely divided carbon, silica, etc can adsorb gaseous matter on their surface to a great extent.

Professor Zhongwei Chen, at the University of Waterloo in Canada has developed optimized carbon powders (spheres) to absorb carbon dioxide, which is the main gaseous emission which is linked to the on-going climate change.  Work is going on to further increase the efficiency of the adsorption process by increasing the size and concentration of pores on the carbon material. Carbon is cost effective, environmental friendly and can be used in any shape and size, like columns.

The ultimate use is to employ the material at the carbon dioxide discharge lines of fossil fuel burning power plants to capture the CO2 gas. After saturation, the carbon can be stored deep underground, at geological formations to prevent its escape into the environment – in competition to disposal of high level radioactive waste in geological formations! 

The system needs to be developed in massive industrial scale to make any significant effect to control climate change. Better option still will be to exploit solar power or wind power to a much larger extent.  It is well know that powders like finely divided carbon and silica can adsorb gaseous matter on their surface to a great extent.

Use of chemical weapons

As per the Geneva Protocol 1925, the use of chemical weapons, through the implementation of the provisions of the “CONVENTION ON THE PROHIBITION OF THE DEVELOPMENT, PRODUCTION, STOCKPILING AND USE OF CHEMICAL WEAPONS AND ON THEIR DESTRUCTION 2005” is prohibited world-wide as a method of warfare for the benefit of mankind.

There are many toxic chemicals /gases which can create devastation/death in areas where the chemical weapons are used. However, chemicals are used often by some governments and other terror organizations to strike terror and induce fear amongst the public at large.  Often, we hear of accidental toxic gas leak causing death of people in the vicinity. Recently, in Douma, Syria chemical weapon was used and so many deaths.  

It is time that the UNSC urgently step-in and enforce the provisions /obligations of the Convention in letter and spirit and ensure that the chemical weapons are never used as a means of warfare or civil war to destroy population groups. The incidents of use of chemicals/chemical weapons should be investigated by UN authorities. Adequate resources for monitoring and for providing medical care for affected should be provided by the rich nations.

Moral decisions and Artificial Intelligence

It is reported that Driverless cars (Self driving cars) are expected to be on Britain’s roads by 2025. The cars can make “life and death” decisions on the roads! How?

So far, robots and other artificial intelligence based systems are being used in hospitals for surgery and other interventional procedures. Now, driverless cars on the roads to take moral decisions in situations where a collision with human being on the road is unavoidable!

A neuroscientist Leon Sutfeld and Prof. Gordon Pipa at the University of Osnabruck, Germany who are working on driverless cars, is stating that Human behavior in dilemma situations can be modeled by a “simple value of life based model that is attributed by the participant to every human, animal or inanimate object”. (Ref. Frontiers in Behavioral Neuroscience, 2017, 11, DOI:10.3389/fnbeh.2017.00122).

The ethical aspect is questionable?  Can machines take human-like moral decisions?

It is true that everybody is expected to follow traffic rules strictly. However, can a driverless car run over a child running on to the road rather than crashing on to an adult standing on the footpath while trying to save the child? Any answers?

“Designer babies” in 30 years?

As per a professor from Stanford University, One need not have sex to procreate! (TOI News dated 5^th July). Parents can choose from a range of embryos created in a lab with their DNA! Body organs can be created in the labs or regrow damaged organs or tissues.

The embryos can be screened for any potential diseases, and can have choice on the color of the hair or the eyes. Certain diseases can be avoided in the future.

Now, where are we heading? No need to marry and gets tied up with one another for life.  Already, some studies have indicated that number of times the married couples having sex has decreased drastically and as of 2014, the number is just 55 times a year. Couples are busy with mobiles or laptops. . Marriage will lose its importance and divorce rates will go up fighting for the type of child the couples would like to have.

The Technology can be misused to create monsters or children without any emotional quotient.

It is time that international organizations such WHO, United Nations wake up to this reality of the technological advances and regulate such activities so the world will not have emotionless monsters, and marriage as an institution will remain for some more time.  

Breath test for alcohol – Airline pilots

 Airline pilots are routinely checked for alcohol (ethanol) content in the breath. Any BAC (breath Alcohol Content) reading above 0.08% (0.08 g in 100 g of blood) is taken as “Under the influence of alcohol” and they are not allowed to fly aircraft and putting so many lives at risk. However, there are a lot of factors that affect BAC such as body weight, fatigue and stress factors.

The public understand that many a times pilots fail this test. What happens after testing positive is anybody’s guess!

I have a few queries:

Ø  Whether due to acute shortage of senior or junior pilots, the “drunk” pilots are allowed to fly?

Ø  What are the responsibilities of the regulators in such cases?

Ø  What happens if the regulators are hand-in-glove with the operation staff?

Only way to safeguard the safety of passengers is to ensure that the regulators are beyond corruption, and provide incentives to the young Indians to take the profession of airline pilots so that at any given time we have enough number of pilots available for recruitment by airlines.  

Air purifiers – HEPA system

In India, air pollution in cities is a major public health concern. Most of the time the levels are reported to be 3 o 4 times higher than the permissible limits. The situation is very grave.

Refer today’s TOI news on air purifiers.

Generally, pollution in the air is made up of a lot of gaseous chemicals -oxides of nitrogen sulphur and carbon, trace elements, some of them are toxic or carcinogenic. There are particulate matter of different sizes (PM₁₀, PM_2.5) there are chemicals, Greenhouse gases (CO₂) vehicular exhausts-mostly organics, smoke particulates, heavy metals etc, etc. The concentration of the pollution in air varies from place to place depending on the location of sources of the pollution, wind velocity and wind direction.

It should be borne in mind that there is no single filter which can remove all these pollutants from the air. High Efficiency Particulate Air (HEPA) Filters are available in the market today to remove about 99% of the particulates of sub-micron size. The so-called advertised HEPA air purifiers are expensive and available for use at home. There are many brands coming in the market. Consumers will be taken for a ride by the advertisements and marketing strategy.

As a consumer, one should ask the following questions:

1.   HEPA is a particulate filter. How it is going the remove gaseous and organic pollutants?

2.    The filter is highly efficient. Due to high dust load, the filter is going get choked within a few days. Replacement of the filters will be very expensive.

3.     In a practical sense, one has to close all windows and doors in rooms, put on AC and then use the HEPA filtration system. Is it practical?

4.     What will be the operational cost per month for say 4 hours a day use?

5.     What happens when the person goes out for daily walk or travel in a car or bus? He will be exposed to the same polluted air outside.

6.  Health issues will be more when you expose your biological systems to very clean air inside a room and highly polluted air outside routinely.

The only way to solve this problem is to reduce the pollution levels below the permissible levels. Every one of us should focus on reducing pollution at the source rather than spending hard-earned money on such air purifiers. 

Age-wise distribution of cancers

It is reported that (TOI, 31^st Jan, 2017) half the cancer patients are in 60 plus age group. It is not unexpected. Cancer is a known old age disease.

There is large increase in the life expectancy of population over the years, i.e., the 2014 world average life expectancy is 71.5years compared to the 1950 world average life expectancy of 48years. Since the latency period (waiting period from induction to development of malignant tumour) of cancer is 20 to 40 years, cancer is seen, in general, after well past 50 years of age. Cancer fatality rate is thus increased, numerically!

Use of suphur or phosphorus in production of sugar

There was a news item in the Sunday Express dated January 3, 2016 on use of sulpur in the production of white sugar. In the process, SO2 is introduced to affect pH control and for clarification / purification of the sugarcane juice. Later in the production, SO2 is used as bleaching agent to get white sugar. Excess SO2 is taken out of the process. However, traces of sulphur is left behind in the sugar. Intake of higher levels of sulhur is known to cause respiratory diseases. Due to this, the production of white sugar using suphur is banned in some countries and the process is carried out using CO2 (carbonation process) using trace amounts of phosphoric acid. However, the sugar produced in this process is brown in color and not white.

Now why in India, people are crazy to buy white sugar? Brown sugar is good for the health and the government should insist on not using SO2 for sugar factories. Sulphur is a critical nutrient and daily dietary intake is around 800 to 900 milligram per day. Higher intakes may be prescribed for patients with arthritis Sulfur-rich foods include meat, eggs, whole grains, garlic, onions, Brussels sprouts, and cabbage. Excess intake may cause stomach problems, embarrassingly, flatulence and kidney problems. 

Phosphorus is the second plentiful mineral after calcium in the body. It is required for many functions in the body such as filtering waste and repairing tissue and cells. Certain health conditions (such as diabetes and alcoholism) or medications (some antacids) can cause phosphorus levels in your body to drop too low. Phosphorus levels that are too high or too low can cause medical complications, such as heart disease, joint pain, or fatigue. If one replaces sulphur with phosphorus, and the residual phosphorus in the sugar too can cause health issues.

Comment:

The quality assurance during the production of sugar, in either case, is necessary to ensure that residual sulphur or phosphorus in the final product should be within the permissible levels. If such levels are not available, it is time that such limits should be prescribed by the authorities and enforced in the sugar factories. CO2 is a by-product in the distilleries normally attached to the sugar factories. The additional benefit of using carbonation process is the use of CO2 (a greenhouse gas) in the process! 

The Paris Agreement-2015

The Paris Agreement, following the 2015 Paris Climate Conference 2015 is about UN negotiated agreement on climate with the aim of keeping the average global warming below 2°C, above the pre-industrial levels. France played a key role in hosting this conference to save the world from the repercussions - risks and impacts of climate change. It is the aim of the conference to restrict the warming at 1.5°C. The countries participated presented their own National Climate Action Plans to reduce the greenhouse gas (GHG) emissions. The progress made by the countries will be tracked through a robust accountability and transparency system.

Governments have agreed to strengthen societies’ ability to deal with the impacts of the climate change, and developing countries will be provided with international support for adaptation of the Agreement by the developed countries.

Developed countries will support developing countries by mobilizing funds of of USD 100 billion per year collectively, until the 2025. The Agreement will be ratified by 55 countries, (giving voluntary target for emission reduction) which account for 55% of the world’s GHG emissions The Agreement is due to enter into force in 2020. Meet every 5 years.   

The top 6 countries which are emitting GHG are: China, United Sates, European Union, India, Russian Federation and Japan.

If France could manage have carbon free electric grids in just 11 years, why not other countries? Policy makers should say NO for fossil-fuel based power. USE ONLY RENEWABLE ENERGY mix, sources, viz. solar, wind and hydro. Until such time, use standardized, modular nuclear power plants and go for nuclear power (fission or fusion) which is also a clean energy source. Enough research is done, now the time to scale-up the technology and implement in a massive scale.  

Water management issues, India

90% of India’s water withdrawal is for use in agriculture and livestock, often extracted by tube wells powered from the grid and drawing from groundwater reserves. High rates of population and economic growth, along with highly inefficient patterns of water use in the agricultural sector, are putting severe strain on India’s water resources. 

Major policy decision needs to be taken to improve upon or preserve the water resources. Some of the actions may be:

1.     Compulsory rain water harvesting

2.     Recycling of water

3.   Connecting the rivers to take water from the northern rivers (normally flooded due to melting of ice during summer) to southern states which suffer from water shortage during summer. 

4.     Judicious use of water in agricultural sector.  

Plastic waste management-A new study

Millions of tonnes of plastic waste, mainly package material is generated world-wide. About 10% of the waste gets recycled and the rest presents an environmental challenge in terms of water contamination and animal poisoning. Plastic is not degradable and hence needs to be stored for longer periods of time and is not environmental friendly. The major constituent in plastic material is polystyrene.

A Stanford Report (Sept. 29, 2015) indicates that an ongoing research in collaboration with researchers in China on plastic-eating worms may offer a solution for safely biodegrade various types of plastic.

The tiny worm, which is the larvae form of the darkling beetle can survive on a diet of Styrofoam and other types of polystyrene.

The study has opened a new door to the management of global plastic waste problem. It is long time to go before the research (in milligram levels) can be put into actual application in massive scale for plastic waste management. This needs to be addressed quickly to protect our environment, including marine life

University of Texas cancer study links meat to kidney cancer

Dr. Xifeng Wu and her team at the University of Texas MD Anderson Cancer Centre investigated the effect of grilled or barbecued meat on the increased risk of kidney cancer. Grilling and barbecuing meat produces carcinogenic organic compounds which increases the kidney cancer risk. It is estimated that 61,000 Americans will be diagnosed with kidney cancer yearly.

American Cancer Society points out the recent IARC (International Agency for Research on Cancer) report that processed meats such as sausages and bacon cause cancer. There is also a genetic component of population groups with high risk of kidney cancer and the meat eating only increases the risk. 

This is an important finding which is going to be discussed for a while. The western countries where grilled and barbecued meat is increasingly used will find it difficult to stay away from this dietary component and will continue with the habit. Like alcohol which is proven carcinogenic but still used worldwide, eating processed meat also will be continued knowing that they are cancer causing! Who cares for the research findings? 

Wireless pacemaker – a new development

A pacemaker is used to restore heart’s rhythm by sending tiny electrical impulses to the heart. Millions of people world-wide who are suffering from slow or irregular heart rhythm, are able to live more active lives due to the restoration of heart rhythm. Roughly 200,000 people in US alone get a pacemaker. These pacemakers have wires (one or two insulated leads) which carry impulses from the pacemakers implanted by surgical incision outside the heart, under the skin.

The new development is a miniature pacemaker (typically Micra TPSystem) fully self-contained, has no leads. and can easily implanted in the heart, with minimum invasive surgery. It is delivered through a catheter inserted in the femoral vein to the inside of the heart. International clinical trials demonstrates high implant success.

Questions to be answered are: the cost, failure rate, removal of the failed pacemaker from the heart and the actual battery life. This is a very good development and efforts should be made to make this novel device affordable, cost-wise.

(This is only for information, Always talk to your healthcare provider for diagnosis and treatment, including your specific medical needs).  

Rent-a-womb tourism

As per the India’s new draft law, Assisted Reproductive Technology (regulation) Bill 2014, only Indian couples or a foreigner married to an Indian citizen can opt for paid surrogacy. By using the word couple, whether homosexuals and people in a live-in relationship are excluded by passing the Bill? Whether this will be in conflict with other provisions of law?  

India will be no longer a fertility tourism hot spot! But there is a positive side to this. As reported in the media, ruthless exploitation of the surrogate mothers rampant in some part of the country, will be curtailed. There is a need for strong regulation to prevent any unethical practices, including responsibility for post-delivery complications. Breakers of the law should be prosecuted and put behind bars. Women’s rights group must take active lead in ensuring strict regulation to protect surrogate mothers rights and bring-in awareness of the health risks.          

It’s getting hotter by the day! What next?

America’s Clean Power Plan launched recently can reduce carbon dioxide emissions from coal/gas based power plants by 870 metric tonnes by 2030. Similarly, Brazil pledged to reduce carbon emissions by 43% by 2030. These reductions are with respect to the levels in 2005. China which contributes major part of the global emissions, is taking steps to reduce emissions.   

Global carbon emissions are higher by 58% in 2012 as compared to the level seen in 1990. Today, atmospheric carbon dioxide concentration is 400 parts per million. At the present rate of emissions, the global average temperature may rise by 4.5 degree C and if countries cooperate, the temperature my still rise by 3-5 degree C by 2100. As per the meteorological agency reports, the deviation from the average global air-surface temperature is 0.75 degree C warmer as compared to 1950 data. Oceans are getting warmer, glaciers are melting and the complexity of changing ocean currents and atmospheric pressure differentials are causing catastrophic effects such as storms, floods, forest fires, crops damage, droughts, etc, etc. The effects of the climate change are seen everywhere.

The next climate change talks will be held in Paris this year end. There will be tussle between developed and developing countries on the quantum of reduction in the greenhouse gas emissions. There is a necessity of a huge global climate fund to compensate poor nations from not using greenhouse gas emitting technologies for their development. Who will contribute and how much?  

If the nations which have good reserves of oil, coal and gas are not able to sell or use them for industrial development, what will happen to the world economy? Who will buy the fossil fuel which will not be allowed to burn? Solar/Fusion power may be the answer!