It shouldn’t be top of your paranoia list. But if you’re a resident of the Cape Town metropole, you’ve thought about it. Perhaps it came to mind during one of the city’s recent blackouts, or perhaps this year, 21 years after Chernobyl, the worst nuclear accident in history.
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What happened at Chernobyl?
On 26 April 1986, one of the reactors at the nuclear power plant at Chernobyl in the Ukraine exploded producing a massive cloud of radiation.
Thirty-one people were killed instantly. Based on official reports, over eight million people in Belarus, Ukraine and Russia were exposed to the radiation to varying degrees. Lower levels of radiation from Chernobyl have been measured as far distant as Scandinavia and the United Kingdom.
Health effects of exposure to nuclear radiation
The following are the main health effects that have been studied with regard to Chernobyl, and are likely to be seen with similar nuclear events:
Radiation sickness. People who receive a sudden very high dose of radiation, such as those working on the reactor at the time of the accident, or involved in clean-up operations afterwards, are at risk of acute radiation sickness (ARS), the result of damage to the body’s tissues and immune system.
Immediate ARS symptoms include nausea, diarrhoea and fatigue. This may be followed by symptoms such as hair loss, bleeding under the skin and mouth inflammation.
In severe cases death may occur within two to four weeks. Those who survive for six weeks after a large dose may generally be expected to recover, but are at risk for long-term effects.
Long-term effects. Radiation can also cause changes to the body's genes, which can lead to the development of diseases such as cancer later in life.
Radiation-related illnesses tend to emerge about 10 to 15 years after a radiation disaster. The most notable such illness attributable to Chernobyl is thyroid cancer: a large increase in incidence has been recorded in the most contaminated areas.
There is considerable uncertainty about many of the other possible health effects attributable to radiation from Chernobyl. The health effects of lower radiation doses are not well understood. The disaster has been implicated in following diseases, however: leukemia, breast cancer, cataracts and heart disease.
Nuclear emergency planning zones
All nuclear power stations have emergency plans in the event of a disaster, and Koeberg’s is along similar lines to others internationally.
In the case of a ‘general emergency’ – one in which radiation cannot be contained within the site and threatens to contaminate the surrounding area, different ‘emergency planning zones’, depending on the level of risk, are recognized. These are as follows (See map for an idea of how these relate to Cape Town):
5km radius of the source: people in this area would be at highest risk for radiation exposure.
16km radius of the source: people could potentially be harmed by direct radiation exposure.
80km radius of the source: radioactive materials may contaminate water supplies, crops and livestock
The above zones are, of course, only a model of most likely risk. There are multiple factors that affect the severity of a general emergency - the nature of the accident, the size of the radiation 'cloud', prevailing wind direction, rainfall and topography.
Koeberg – like many power stations on the US and Europe - has plans for up to the 16km radius. If a general emergency is declared, Koeberg assures us those living within the 16km radius (and even more so within the 5km radius) will hear sirens and loudspeakers advising them what to do. If you live in either of these zones, you should also be issued an ‘emergency calendar’ every year.
It’s not certain what the plan would be for anywhere beyond the 16-km zone. This probably wouldn’t be too problematic in the case of a small radiation leak. But if larger incident occurred, might very well be another matter. The exclusion zone around Chernobyl – the area most contaminated, from which the population was evacuated - was a 30km radius, and lower levels of radioactive material was deposited for hundreds of kilometres further than that.
Growing city puts more people at risk
Maya Aberman, campaign co-ordinator of Earth Life Africa (ELA), which has a strong anti-nuclear power agenda, points out that most nuclear power stations in the world are not situated so close to a metropolis.
“Spatial development is putting more people at risk. Cape Town is expanding at an alarming rate, and has few places in which to expand except up the west coast. And the plan is to extend the life of Koeberg, by building a pebble bed modular reactor and another conventional reactor.”
Increased urban development would also make an evacuation, should that be necessary, more difficult. “The rolling blackouts showed that we don’t have the means to evacuate Cape Town,” says Aberman. We’ve seen during the blackouts that the traffic couldn’t handle that – imagine that situation on top of the panic during a disaster”.
Aberman says ELA attended Koeberg’s last two emergency planning meetings: “We weren’t impressed. Communication is poor and many people are not clear about the process and implications.”
No protection from thyroid cancer
One of many issues ELA has found problematic with Koeberg’s emergency planning is that of lack of provision of potassium iodate*.
These tablets, which help protect against thyroid disease caused by contamination with radioactive iodine, one of several radioactive substances likely to enter the environment in a general emergency. Increased rates of thyroid cancer are the most striking health impact attributable to the Chernobyl disaster.
Koeberg does not issue the tablets; they claim that these will be issued in a general emergency should it be deemed necessary. However, potassium iodate needs to be taken very soon during a radiation emergency to be effective, and ELA says that stocks of the medication are not available.
“The Department of Health had a stock of potassium iodate, but they expired,” says Aberman. “As far as we’re aware, people don’t have access to tablets.”
Take back the power
One reason the threat of a nuclear disaster is so troublesome – as opposed to driving a car, for instance, which is statistically far riskier – is that with driving you have the illusion of control over events. Having your own personal game plan in case of disaster, is, if nothing else, good for your mental health because it makes you feel less helpless.
And there really are ways you can reduce your radiation dose, potassium iodate or no potassium iodate, should you ever need to. The three factors to remember are distance, shielding and time.
Distance. The further away you can get from the source of the radiation, the better. If you’re told to evacuate, keep car windows and air vents closed; use re-circulating air. Keep your petrol tank full and your car serviced. Good in case of evacuation, or just a power outage that disables the petrol pumps.
Shielding.It may be better to stay put indoors when the accident happens. The aim is to put a ‘shield’ - a barrier of dense, heavy material like a wall or earth - between yourself and the radiation source. Ideally, get to a basement or other underground area. You should also:
Close off air intakes: doors, windows, air conditioners, fireplace flues etc.
Keep food in covered containers or in the fridge (though that's unlikely to be working at a time like this). Food not previously covered should be washed before being put in to containers.
If you think you’ve been exposed to radiation:
Take off any exposed clothing and shoes and put them in a plastic bag. Seal this and put it out of the way.
Have a shower and wash yourself really well.
Time. Radioactivity decreases over time, so the longer you can avoid going outside, the better. Radioactive fallout poses the greatest threat during the first two weeks, by which time it has reduced to about 1 percent of its initial level. Any survivalist worth his or her salt will have supplies to last for at least a fortnight.
It’s very important to be able to listen to broadcasts, which will advise as to the best course of action. So a battery-operated radio - a vital piece of equipment in any disaster that causes a power outage - is a good investment. As is a battery-operated torch.
*Potassium iodate should only be taken in an emergency and when advised by medical personnel. Some people are allergic to iodine.
Olivia Rose-Innes, EnviroHealth Expert, Health24, April 2007
Information sources:
Health Effects of the Chernobyl Accident and Special Health Care Programmes: Report of the UN Chernobyl Forum Health Expert Group World Health Organization, Geneva, 2006.
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