일본은 후쿠시마 핵발전소사고로 최근 성인 300 Bq/L 영아 100Bq/L 로 기준을 상향조정했다
반면 세계보건기구는 10Bq/L
FAQs: Japan nuclear concerns
5 April 2011
Water contamination
Can I drink the tap water in Japan?
- Drinking tap water in Japan poses no immediate health risk, but local conditions will differ and may fluctuate.
- The Japanese authorities are closely monitoring the situation and
are issuing advice, when needed, against consumption of tap water,
including specific recommendations for infants. Essential hydration of
infants should not be compromised in an attempt to reduce exposure to
radionuclide contamination. - The standards adopted by the Japanese authorities for this
emergency are precautionary. Currently, radioactive iodine is the most
common detected contaminant; the standard for adults is 300 Becquerels
per litre in drinking-water. In the very unlikely scenario that
drinking-water was contaminated and consumed for an entire year at this
level, the additional radiation exposure from this water would be
equivalent to natural background radiation during one year. - WHO urges people in the area to heed the advice of local
authorities, as they will have access to the latest measurements of
radiation levels in water to compare against the standards for adults
and children.
Can radioactive contamination be removed from water?
- Standard water treatment procedures may remove significant
amounts of radioactive contaminants. Other options to reduce
concentrations of radiation contaminants include controlled dilution of
contaminated water with non-contaminated water. - Boiling water will not remove radioactive iodine.
Why do the guidance levels for radioactive Iodine-131 in drinking water vary?
The guidance levels found in different sets of recommendations
vary because some apply to routine situations and others to emergency
situations. The table below summarizes the guidance on radioactive
Iodine-131 in drinking water and provides an indication of the
equivalent exposure from routine activities.
| Guideline name | Advised maximum levels for radioactive activity in water (Bq/L) | Approximate equivalent radiation exposure if consuming water at this activity level for a year |
| WHO Guidelines for Drinking-water Quality (1) | 10 | A New York – London flight |
| Japanese provisional (emergency) standard for adults (2) | 300 | One year’s exposure to natural background radiation, or 10-15 chest X-rays |
| Japanese provisional (emergency) standard for infants (3) | 100 | |
| IAEA Operational Intervention Level for nuclear emergencies (4) | 3000 | Not applicable. The advised maximum level should be used only to trigger action in the early stages of the emergency |
(1) WHO Guidelines for Drinking-water Quality should not be
taken as the reference point for nuclear emergencies because the levels
set are extremely conservative, and designed to apply to lifetime
routine intake.
(2) Provisional regulation values relating to limits on food
and drink ingestion, established by the Japanese Food Sanitation Act, as
indicated by the Nuclear Safety Commission of Japan.
These standards are precautionary and have taken international guidance
into consideration, including recommendations of the IAEA and the
International Commission on Radiological Protection.
(3) As in (2) above, but applicable to drinking-water used to
prepare baby food. This level is equivalent to the international
guideline set by Codex Alimentarius for infant food.
(4) IAEA Safety Guide GSG-2 established Operational
Intervention Levels (OILs) which would be the default international
guidance levels for the early stage of an emergency.
