Air exposures calculation details

The long term (chronic) air exposure assessment through inhalation is related to exposure to substances in air. MCRA applies in principle the equations as used in RSExpo.

Inhalation exposure

The calculation for inhalation exposure is:

\[\mathtt{E_{air-inhal}} = \frac{ 1 }{ \mathtt{BW} } \cdot \mathtt{F_a} \cdot \left[ \mathtt{c_{in,a}} \cdot \mathtt{t_{in}} + \mathtt{c_{out,a}} \cdot ( 1 - \mathtt{t_{in}} ) \right]\]

Parameters used in the equation

\(\mathtt{E_{air-inhal}}\): average daily external exposure of an individual to substances by air inhalation (default in \(\mu g/kg \, bw /day\))

\(\mathtt{BW}\): body weight of the individual (default in \(kg\))

\(\mathtt{F_a}\): daily ventilatory flow (\(m^3/day\))

\(\mathtt{t_{in}}\): fraction of daily time spend indoors

\(\mathtt{c_{in,a}}\): substance concentration in indoor air (default in \(\mu g/m^3\))

\(\mathtt{c_{out,a}}\): substance concentration in outdoor air (default in \(\mu g/m^3\))