Sir.—Inhalation of environmental contaminants bears a risk of immediate systemic toxicity. The lungs are a vulnerable shortcut through which airborne toxins may bypass the body's defense mechanisms. Hazardous gases and particles rapidly penetrate alveolar membranes and capillary walls, reaching the systemic circulation within seconds.1
Respirators of various kinds are used in industry to protect employees from occupational exposure to hazardous substances. In large-scale toxicologic disasters2 or implementation of chemical warfare agents,3 the entire civilian population in the surrounding environment is threatened by highly toxic chemicals. The unique requirements of small children must be taken into consideration when supplying protective respiratory devices to the general population. Children are expected to be particularly intolerant of functional problems associated with ordinary gas masks, such as respiratory resistance, visual restriction, claustrophobia, and difficulties in optimal fitting of the mask.4,5
A special protective respiratory mask (Bardas, Shalon Chemical Industries Ltd,