Health Effects of Mercury

Health Effects of Mercury

 

■  Health Effects

Mercury can cause various toxic effects in the human body, such as increased risk of cardiovascular diseases, birth defects, kidney toxicity, and nervous system damage. The International Agency for Research on Cancer (IARC) classifies mercury as a possible human carcinogen. Infants and children are particularly sensitive to mercury exposure.

Chronic exposure to mercury, known as mercurialism, typically results from exposure to metallic mercury or inorganic mercury, affecting primarily the nervous system, mouth, and kidneys. Symptoms include fine tremors, shyness, emotional instability, and neuropathy. Organic mercury poisoning, different from typical mercurialism, mainly causes neurological disorders like weakness, numbness, speech and walking difficulties, and visual field constriction.

Exposure to mercury during pregnancy can transfer mercury directly to the fetus, leading to severe conditions such as cerebral palsy and psychomotor retardation in newborns. Even at low concentrations, higher maternal mercury levels can result in lower birth weight, delayed growth, and cognitive development issues in children.

 

■   EPA-FDA Advice about Eating Fish and Shellfish

For pregnant women and nursing mothers, consuming fish is important for nutrition, but it's advised to limit the intake of high-mercury fish to once a week, and opt for low-mercury fish two to three times a week. In addition to fish consumption, dental amalgam is another major source of mercury exposure for the general public. It's important for these groups, in particular, to be aware of their mercury exposure due to the potential risks to developing fetuses and young children.

<EPA-FDA Advice about Eating Fish and Shellfish (1)>

 

■  Reference values

Blood mercury levels reflect recent exposure, while urine mercury levels better indicate chronic exposure (over 6 months). The German Human Biomonitoring Commission recommends blood mercury levels of HBM I – 5 µg/L and HBM II – 15 µg/L; for urine mercury levels, HBM I - 5 µg/g cr. and HBM II - 20 µg/g cr (2).

• HBM-I represents a concentration level at which there is no health risk for the general population, while HBM-II indicates a concentration level at which there is a health risk, suggesting the need for exposure reduction and continuous medical monitoring for the sensitive subgroups within the general population.

■   References

The content is primarily based on Casarett and Doull’s Toxicology 9th edition and Mercury Substance report.

(https://www.hbm4eu.eu/wp-content/uploads/2022/07/Mercury_Substance-report.pdf ).

(1)   EPA-FDA Advice about Eating Fish and Shellfish: https://www.epa.gov/choose-fish-and-shellfish-wisely/epa-fda-advice-about-eating-fish-and-shellfish). Access date: 2024-03-01

(2)   Human biomonitoring (HBM) values derived by the Human Biomonitoring Commission of the German Environment Agency, status june 2023: https://www.umweltbundesamt.de/sites/default/files/medien/4031/bilder/dateien/kopie_von_hbm-werte_engl._stand_sept._2023.pdf. Access date: 2024-03-01