Elárulom, régen sokkal kevesebb ilyen jellegű probléma volt, a második világháború után kezdett népbetegséggé válni és hihetetlen mértékben elterjedni a fejlett nyugati országokban. Több elmélet is van a kialakulásának okára, és a szennyezettség, kemikáliák nagy mennyiségű használata (egyesek szerint gyógyszerek, vakcinák is hozzájárlnak) mellett van egy nagyon fontos dolog is amit itt senki sem említett és sajnos nincs benne a köztudatban ami aztán majd kitermeli az új allergiás nemzedéket. Ez pedig a túlzott tisztaság/fertőtlenítés/gyerek széltől is óvása. Így nem kapja meg élete első pár évében, amikor kialakul az immunrendszer a kellő mennyiségű fertőzést, amitől az 'megtanulhatná', h mi ellen is védekezzen.
"The hygiene hypothesis
One theory that has been gaining strength is the "hygiene hypothesis". This theory maintains that since children in more affluent countries are leading a cleaner and cleaner life (less exposure to dirt, extra use of disinfectants, etc), their immune systems have less exposure to parasites and other pathogens than children in other countries or in decades past. Their immune systems may, therefore, have many "loaded guns", cells which might have targeted, say, the intestinal worms that no longer cause trouble in affluent neighbourhoods. Having no reasonable target, these cells inadvertently become activated by environmental antigens that might only cause minor reactions in others. It is the symptoms of this exaggerated response that is seen as the allergic reaction.
Many common allergies such as asthma have seen huge increases in the years since the second world war, and many studies appear to show a correlation between this and the increasingly affluent and clean lifestyles in the West. This is supported by studies in less developed countries that do not enjoy western levels of cleanliness, and similarly do not show western levels of incidences of asthma and other allergies. During this same period, air quality, at one time considered the "obvious" cause of asthma, has shown a considerable improvement. This has led some researchers to conclude that it is our "too clean" upbringing that is to blame for the lack of immune system stimulation in early childhood.
So far the evidence to support this theory is limited."