This can trigger a reaction in those with a genetic disposition to allergies - causing hayfever, asthma and eczema.

There are several factors that might elevate blood results, such as genetic disposition, natural biological variation, analyser error, altitude exposure and acute illness.

The findings indicate that environmental factors are involved along with a genetic disposition.

Before initial employment in the platinum salt areas, a medicalscreening procedure was undertaken so as to avoid employing people who had a genetic disposition to allergy.

Physical factors like genetic disposition are another common possible explanation.