Table 3:

Health Canada and Quebec mercury guidance values and recommended actions²

Group	Total mercury level		Recommended actions
	In blood	In hair
Women of child-bearing age Children < 18 yr	< 8 μg/L (< 40 nmol/L)	< 2 μg/g	No follow-up required
	8–40 μg/L (> 40–200 nmol/L)	> 2–10 μg/g	Repeat blood/hair test immediately in pregnant women; otherwise repeat in 3–6 mo Identify dietary sources of exposure and provide dietary advice, taking into account social importance of wild foods If food insecurity or micronutrient deficiency is a concern, consult with nutritionist or dietitian for low-mercury, high-nutrient food options
	> 40–100 μg/L (> 200–500 nmol/L)	> 10–25 μg/g	Repeat blood/hair test immediately Identify dietary sources of exposure and provide dietary advice, taking into account social importance of wild foods If food insecurity or micronutrient deficiency is a concern, consult with nutritionist or dietitian for low-mercury, high-nutrient food options
	> 100 μg/L (> 500 nmol/L)	> 25 μg/g	Repeat blood/hair test immediately Request mercury speciation in whole blood to discriminate dietary methylmercury from inorganic mercury exposure If inorganic mercury, identify environmental sources of exposure and seek solutions with patient to eliminate exposure If methylmercury, identify dietary sources of exposure and provide dietary advice If accompanied by symptoms of mercury exposure, refer patient to an expert (medical toxicologist or neurologist)
Women > child-bearing age Men > 18 yr	< 20 μg/L (< 100 nmol/L)	< 5 μg/g	No follow-up required
	20–100 μg/L (100–500 nmol/L)	> 5–25 μg/g	Repeat blood/hair test in 3–6 mo Identify dietary sources of exposure and provide dietary advice, taking into account social importance of wild foods If food insecurity or micronutrient deficiency is a concern, consult with nutritionist or dietitian for low-mercury, high-nutrient food options
	> 100 μg/L (> 500 nmol/L)	> 25 μg/g	Repeat blood/hair test immediately Request mercury speciation in whole blood to discriminate dietary methylmercury from inorganic mercury exposure If inorganic mercury, identify environmental sources of exposure and seek solutions with patient to eliminate exposure If methylmercury, identify dietary sources of exposure and provide dietary advice If accompanied by symptoms of mercury exposure, refer patient to an expert (medical toxicologist or neurologist)
All groups (Quebec only)	≥ 12 μg/L (≥ 60 nmol/L)	≥ 3 μg/g	Test result must be declared to regional public health authority (consult steps to be taken at www.msss.gouv.qc.ca/professionnels/mado/demarche_medecins.php)