Hi. I want to calculate the carcinogenic and non-carcinogenic risk (HI and CR) based on the reference concentration (Rfc) and the inhalation unit risk (IUR). But I do not know the pollutant concentration (ppmv) in air should be converted to mg/m3 at which temperature (such as 25 ℃), that is, the Rfc and IUR are measured at what condition (temperature).

Could anyone send me the related reference?

Many thanks.