TOKYO — When one thinks of Japan, culinary specialties often come to mind. Unsurprisingly, many of Japan’s best foods rely on the excellent water quality in Japan. Soba noodles, Japanese sake, dashi and even sushi rice are all dependent on the crispness and clarity of the water found in Japan. In fact, of all water used in the agriculture sector, more than 90 percent is used for rice paddy irrigation.
The country is lucky to have a high level of precipitation, with a mean annual precipitation level of 1,700 millimeters compared to the global average of 900-1000 millimeters. In a report on water quality in Japan, the Water Environment Partnership in Asia states “the recycling of industrial water has been developed. As a result, the amount of water that has to be additionally taken from water sources, such as rivers, is gradually decreasing.”
There are seven government-designated river systems from which Japan draws its water. The Japan Water Agency has managed these sites for more than 40 years and, as of January 2017, has completed 63 projects either to construct or reconstruct facilities, dams and canals.
Following the Fukushima accidents in March 2011, Japan has upgraded its water purification system. A 2016 article from the Nippon Communications Foundation revealed that “Japan’s regulations for public water supplies are more stringent than those governing bottled spring water.” Legally, the Ministry of Health, Labor and Welfare requires 51 different tests for toxicity, harmful contaminants, tint, clarity and smell.
Tokyo Waterworks goes even further, setting about 200 safety and quality parameters for itself. Not only does the company run several preservation projects for forests around water sources, but it goes so far as to offer bottled Tokyo water to display the superiority of the tap water produced by its facilities.
Although Japan does not desalinate water from the ocean to drink, marine life is a massive part of the Japanese diet. Not to mention the enormous tourist industry centered around the famed quality of Japanese fresh fish, which is directly linked to the water quality in Japan. The Center for Marine and Environmental Radiation has been closely monitoring the damage caused by the March 2011 tsunami to the Fukushima Dai-ichi Nuclear Power Plant. The damage from the plant leaked several radioactive elements, such as Cesium-134 and Cesium-137, into the ocean. The organization has been monitoring the chemical contamination decline and its spread toward North America through the Pacific Ocean.
It is important to note that not only do small quantities of radiation occur naturally but hardly any Pacific Ocean water does not have at least small traces of Cesium-137, due to both its 30-year half-life and past nuclear bomb testing in the 1950’s, 1960’s and 1970’s. Cesium-134, which has a much faster half-life of 2 years, is unique to Fukushima. Scientists can measure the specific radiation from Fukushima by comparing the two.
A study in January 2017 showed the area of the ocean affected by Fukushima had 12 percent of the original caesium-134 released during the accident almost six years prior. CMER has since introduced a new piece of technology called the RadBand, which is used to monitor the radioactivity in seawater, allowing anyone going into the ocean to take part in gathering data for important research.
Most of the contaminated fish stay close to the area around the Fukushima reactor where fishing has since become prohibited, but the far-ranging fish like Bluefin Tuna can migrate farther off the coast of Japan. These fish naturally flush out isotopes like Cesium, but other types of contaminants can remain. The Center for Marine and Environmental Radiation is hopeful. The “Should I Be Worried” section of its homepage states: “Except for locations on land in Japan and sites near the Fukushima Dai-ichi nuclear power plant, all of these sources combined pose little risk to human health.”
– Katherine Gallagher