Air pollution isn't restricted to areas with factories and heavy traffic. Though it may nestle in a rural idyll, your home itself could be a potent source of potentially harmful chemicals.

The phenomenon of "sick-house syndrome," caused by exposure to volatile chemicals given off by building materials, first came to public attention in the 1980s. However it is only in the past decade that it has become a serious concern, as more people complain of ailments that seem to be related to their living environment. According to the National Consumer Affairs Center of Japan, the number of inquiries related to sick-house syndrome jumped from 11 in 1989 to 263 last year.

Symptoms vary. The most frequently reported is eye irritation developed while living in newly built or purchased houses. Headaches, sore throats, itchy skin, heavy coughing and fatigue are also commonly cited conditions.