5.1.1 Trigger avoidance
A very safe, cheap and adequate treatment option is the avoidance of triggering agents 62. For AR patients, this means allergen avoidance, but for all athletes suffering from NHR, exposure to unspecific triggers such as airway irritants, pollution and cold temperatures should be circumvented whenever possible. For some athletes this may be hard to accomplish; winter sport athletes cannot avoid exposure to cold temperatures and outdoor athletes will always be exposed to pollens and/or pollution. Also, for swimmers, exposure to chlorination products is basically unavoidable. In indoor pools, trichloramine is the chlorination byproduct that is most closely related with respiratory symptoms 63, 64 and the WHO regulations demand a maximum level of 0.5 mg/m3trichloramine in the air of indoor swimming pools 65. Yet, in most countries regular monitoring of swimming pool water and air is rarely performed.