- a disposition in advance to react in a particular way
- Other factors such as age, genetic predisposition, the level of physical activity, the consumption of tobacco and other drugs, environmental exposure and stress may all influence the onset of human diseases.
- Evaluation of human data must therefore be carried out with caution, as the frequency of cases reflect, in addition to the intrinsic properties of the substances, factors such as the exposure situation, bioavailability, individual predisposition and preventive measures taken.
- These groups comprise those who are innately more susceptible to the effects of exposure to particulate matter (e.g. those with genetic predisposition, very young children, aged people, people with respiratory disorders and lung diseases), those who become more susceptible as a result of environmental or social factors or personal behaviour and those who are exposed to unusually large amounts of air pollutants as a result of living near a main road or spending long hours outdoors.