What of damp and mould?
Building faults such as rising damp, leaking roofs and gutters, and poor ventilation, lead to higher levels of housedust mites and moulds in the home. Because of this, people who live in damp homes or homes that have high levels of indoor moulds often report more respiratory symptoms than would be expected. Household items that increase humidity, such as fish tanks or humidifiers, are likely to increase allergen levels.