Mercury Urine Testing

Heavy Metals · Heavy Metals overview

Urinary inorganic mercury is the standard biomarker for occupational exposure to elemental and inorganic mercury in chlor-alkali residue, scientific instrument repair, dental amalgam manipulation, and certain chemical operations.

Mercury species and biomarker selection

Elemental Hg⁰ vapour and inorganic Hg²⁺ salts both produce urinary inorganic mercury. Methylmercury (predominantly dietary) is excreted via faeces and does not appear meaningfully in urine, so urinary Hg is specific to the occupationally relevant species.

Reference values and timing

ACGIH BEI is 20 µg/g creatinine pre-shift, reflecting the multi-day urinary half-life and the integration window appropriate to chronic exposure. HSE has not published a BMGV for mercury; UK programmes default to the ACGIH BEI.

Sampling and analysis

Urine in acid-washed containers, analysed by cold-vapour AAS or ICP-MS. Pre-shift sampling avoids the recent-exposure spike from same-day inhalation and provides a more stable cumulative indicator.