From the Guidelines
Elevated urine arsenic levels with normal blood arsenic levels typically indicate past arsenic exposure rather than acute poisoning, and the most likely cause is recent seafood consumption, as evidenced by studies such as 1 and 1. This finding is common because arsenic is rapidly cleared from the bloodstream and excreted in urine, while blood levels return to normal within days after exposure. The source of arsenic exposure should be investigated, with common culprits including:
- Certain foods (particularly seafood, which contains non-toxic organic arsenic)
- Contaminated drinking water
- Occupational exposure
- Certain herbal remedies If seafood consumption is suspected, a speciated arsenic test can differentiate between toxic inorganic arsenic and harmless organic forms, as discussed in 1 and 1. Management involves:
- Removing the source of exposure
- Monitoring urine levels until they normalize Chelation therapy with agents like succimer (DMSA), dimercaprol (BAL), or DMPS is generally reserved for cases with symptoms of arsenic toxicity or very high levels, and should be administered under medical supervision, as noted in 1. Follow-up testing is recommended 2-4 weeks after removing the exposure source to confirm decreasing levels. Patients should be educated about potential arsenic sources and advised to avoid them to prevent future exposure. Key points to consider include:
- The rapid absorption and metabolism of arsenolipids, as described in 1
- The potential toxicity of certain arsenic metabolites, such as thio-DMA(V), as discussed in 1
- The importance of speciated arsenic testing to differentiate between toxic and harmless forms of arsenic, as highlighted in 1 and 1.
From the Research
Arsenic Poisoning and Elevated Urine Arsenic
- Elevated urine arsenic levels can indicate exposure to arsenic, which can occur through various routes including diet, contaminated water, air, soil, and occupational exposure 2.
- Arsenic poisoning can cause a range of health effects, including skin lesions, cardiovascular symptoms, and multi-organ failure 3.
- In cases of acute arsenic poisoning, chelation treatment with therapeutic dithiols, such as DMPS, may be effective in alleviating symptoms 3, 4.
Blood Arsenic Levels
- Normal blood arsenic levels do not necessarily rule out arsenic poisoning, as arsenic can be rapidly cleared from the blood and excreted in the urine 4.
- Elevated urine arsenic levels can be an indicator of recent arsenic exposure, even if blood arsenic levels are normal 2.