​Flame retardants are prevalent in a multitude of common household products, including beds/ mattresses, couches, chairs, carpets, children’s clothing, baby toys and electronics.  They are used to reduce the speed with which consumer goods can be consumed by fire. The chemicals migrate out of household products, and are inhaled as dust, or ingested by young children who put things in their mouths. The Centres for Disease Control recently detected flame retardants in the blood or urine of virtually every person tested for the substances. A study published in 2013 found elevated cancer risks among firefighters exposed to high levels of flame retardants during house fires. There is growing concern about the widespread use of such chemicals, after studies linking flame retardants to cancer, lower IQ, developmental problems, and decreased fertility. In 2013, the EPA was urged to carry out a review on the safety of 20 flame retardants used in a host of common household items[5]. The task of balancing fire safety and health impact of toxic substance in flame retardants is challenging. Before safe alternatives are found, flame retardants remain among the most threatening pollutants in our household.[6]​

Diesel exhaust in indoor air is largely from road traffic. It is a complex mixture of gases and fine particles that contains more than 40 air contaminants. These include many known or suspected cancer-causing substances, such as benzene, arsenic and formaldehyde. It also contains other harmful pollutants, including nitrogen oxides (a component of urban smog). In 2012, the international Agency for Research on Cancer (IARC), part of WHO, classified diesel engine exhaust as carcinogenic to humans. Tiny diesel exhaust particles alter immune function and increase asthma severity in children, and are associated with lethargy in offspring. [2]

Wood smoke: Incomplete burning of wood creates PAH (polycyclic aromatic hydrocarbons) including Benzo(a)pyrene (BaP). Just as 'every cigarette is doing you damage', every gram of wood smoke or other particle emissions is also causing health problems. Wood smoke is more hazardous than cigarette smoke – in tumour initiation tests it was found to cause 12 to 30 times as many cancers as the same amount of cigarette smoke. The estimated health cost of each kg of PM2.5 emissions in Sydney is more than $235 [7].