Air pollutants from highly industrialised areas, cigarette smoking, motor vehicles exhaust fumes, changing feeding practices (refined foods) and changing fuel for combustion (anthracites and coal) have been implicated in the increased prevalence of asthma.
Izinto ezingcolisa umoya ezivela kwiindawo zoshishino, umsi wecuba, umsi okhutshwa ziimoto, ukutshintsha iindlela zokutyisa umntwana (ukutya okucolisisiweyo)kunye nokutshintsha izinto zokubasa (amalahle avutha engenamsi nadangatye kakhulu kunye namalahle) zonke zizinto ezingunobangela wokunyuka kokuhlaselwa kwabantu ngumbefu.