含よう素泉

At least 10 mg/kg of iodide — a class newly created by the 2014 revision of the guidelines, so it appears on fewer certificates than its actual distribution warrants. Common in the Kanto plain and around natural-gas fields. Yellows as it oxidises. Where drinking is permitted it is associated with lowered total cholesterol.

What it is like

Pale yellow to amber, with a medicinal smell much like antiseptic — not unpleasant, but startling if unexpected.

Indications (適応症)

Where drinking is permitted: high cholesterol

Contraindications (禁忌症)

Avoid drinking if you have a thyroid condition. Approach bathing cautiously with an iodine allergy.

適応症 and 禁忌症 are the claims a certificate is permitted to state under the Hot Spring Act. They are not medical advice, and nothing here is. If you have a heart condition, are pregnant, or are unwell, ask a doctor rather than a guidebook.