I want to tell you about some simple agricultural countermeasures, these are the ways in which farmers can change the way they behave to lower the level of the radioactive contamination in the food which they make. I imagine that a lot of farm workers in Japan are normal men and women who want to earn a honest living and that the events right now are a deep source of worry to them. They may be asking themselves if they are going to be forced to give up their way of life because of this accident.
I have read on the BBC that radioactive iodine has been found in food stuffs in Japan. This is not a good thing to have happened. The IAEA site stated that it was radioactive iodine. I have no idea how much radioactive iodine has appeared in the food or what the limit is in Japan for radioactivity in milk.
The iodine could pose some threat to health, the Japanese government have introduced rules controlling the sale of food from the affected area.
My advice now to food producers is not to panic, even if the food is not fit for human consumption now it may be possible to improve the radiological quality of the food in the following way. If the milk only contaminated with radioactive iodine then it could be converted into cheese. The cheese if it was stored for 80 days would then have 1000 times less radioactive iodine in it as a result of radioactive decay.
If you are a dairy farmer in an affected area my advice is ask the authorities in your area before you start cheese making. While it is one method the authority might rather a different method is used to protect the public’s health.
If the accident gets worse and cesium is released then while cesium contamination is a more long lived problem. But there is a way out of the problem, Prussian Blue is a cheap non toxic chemical which can be fed to farmyard animals and humans. What it does is to increase the rate at which the radioactive cesium is lost from the animal or human. If you do want to use prussian blue then make sure that you get the right grade, the pigment grade used in paint is not as good as the special medical grade.
Another method for protecting dairy farming is to deeply plough the grass fields where the cows graze. This is a method which should not be done now while the nuclear accident is still occurring. After the nuclear accident is over and the cesium has stopped being deposited onto the land, then if you do choose to deeply plough then this should start.
The reason why deep ploughing works is this, the cesium is very immobile in most soils so it stays in the top layer where the roots of the grass is. If the soil is deeply ploughed up to mixed the different layers up then the majority of the cesium is then buried below the point to which the grass roots can grow. As a result because the grass roots are now in soil which has a lower average radioactive cesium content in terms of Bq per litre the grass which now grows on the land will be less radioactive.
If the grass is less radioactive then the cows which eat the grass will be less radioactive, and finally the milk and meat will be less radioactive.
In some cases a farmer might want to consider changing from growing food to growing a non food crop. This may help some farmers to containue to earn a living.