Table 2.

Matrices commonly used for measuring exposure to substances and factors to consider when measuring.

Substance	Measured in	Remarks
PAHs [7,18,30,64]	Urine1, other body fluids	Possible to measure several PAHs or their metabolites. Most commonly used biomarkers 1-hydroxypyrene and 1- and 2-napthols. Half-life 5 h–17 d
Diisocyanate [8,25,35]	Urine1, skin tests (Prick), blood tests (adducts, IgE, IgG), serial peak expiratory flow (PEF) measurement at work place, specific inhalation challenge to diisocyanates	Urinary diamines, haemoglobin and albumin adducts and IgE used to measure exposure, other sensitization
Cr(VI) [25,38,69]	Urine1, whole blood, plasma or red blood cells	Measurement of urinary, whole blood or plasma chromium levels is not specific for Cr(VI) exposure since also exposure to Cr(III) affects the levels. Only red blood cell chromium can be considered a specific biomarker for Cr(VI)
Pesticides [25,43,64]	Urine 1	Variable group of compounds, biomonitoring possibilities vary
Phthalates and metabolites [6,48,64]	Urine1, blood, saliva and breast milk	Non-persistent and have a short half-life in the body, therefore the levels of phthalate metabolites show a high daily variation
PFASs [9,25,53]	Blood (serum)1, breast milk, urine	Ubiquitous and persistent pollutants with a long half-time in blood Multiple different substances, biomonitoring methods not available for all
p-PDA [19]	Blood (IgE)1, patch test, lung function testing, inhalation challenge test	Measures sensitization, no validated methods available for the biomonitoring of exposure although some published reports on the measurement of its metabolites in urine or blood available
Mercury [25,38,64]	Blood1, scalp hair, urine	Different states have different kinetic properties Half-life in blood 1–3 weeks for inorganic and elementary mercury and 50 days for methylmercury
Cadmium [25,38,64]	Urine1, blood, placenta (exposure in pregnancy), faeces	Urinary analysis of cadmium levels reflect long-term accumulation Individual factors (sex, age, diet, smoking, metabolism etc) influence the concentration of cadmium in urine Half-life varies depending on organ/matrix, for instance 10–40 years in kidneys
Arsenic [25,38]	Urine1, blood, hair	40–60% eliminated through urine, different forms of arsenic (MMA, DMA, As5+, As3+) can be measured in urine.
Lead [25,38,64]	Blood1, long term exposure: bone, teeth, hair, nail	The half-life generally long but varies between different organs, for instance in adult the half-life in blood approximately 1–2 months and in bones 10–30 years

¹ The most important matrix bolded.