Certain fungi, such as mushrooms, can produce poisonous toxins that may prove fatal if ingested (e.g. Amanita phalloides "death cap") Others (e.g. Psilocybe) affect the central nervous system inducing hallucinogenic responses.
Outbreaks of disease caused by chemical substances are rare, apart from intoxication caused by consuming poisonous fungi. In some CCEE and NIS with a tradition of collecting and consuming wild mushrooms, the death toll from mushroom poisoning reaches hundreds of people each year.
As surely as the first of the daily bulletins on the number of people who have frozen to death "so far this winter" heralds the start of the long freeze, the first reports of mushroom poisoning mark the onset of summer in Russia. Gathering the traditional mushroom feast is a dicey variation of Russian roulette which claims several thousand lives every summer. Bely grib, the much-prized Russian white mushroom, for example, is virtually indistinguishable from the deadly poisonous bledny grib. For every bely grib there is a poisonous one nearby. Even the traditional salting process can cause botulism if the recipe goes slightly awry.
Mushroom-gathering, known in Russian as the tikhaya okhota, or the gentle hunt, unites all classes and all ages. To accuse a Russian of not knowing his mushrooms is tantamount to a combined assault on his manhood and his motherland. A man who gets his mushrooms wrong is an impostor, probably a townie: the sort of person who carries a plastic bag and rips up the mushrooms without due deference, destroying the intricate root network in the process. And buying safe mushrooms, cling-wrapped from a reputable shop -- that's like watching fishing on television.