Winifred A. Bird and Jane Braxton Little
On this evening a year and eight months after multiple explosions at the Fukushima Daiichi Nuclear Power Plant, the men are grappling head-on with one of the most widespread and complex environmental health threats Japan has ever faced: Before fallout released by the March 2011 explosions arrived in the cities that line Fukushima Prefecture’s central corridor, it drifted northwest over the small, cultivated valleys, meandering creeks, and post-and-beam farmhouses of the Abukuma Mountains.2 The region’s residents depended on this land for clean water, wild foods, and firewood. Forests and wooded neighborhoods like Kanno’s are at the center of the dilemma.
The questions Kanno and his neighbors are asking about their forests and their families’ health resurface again and again at local, prefectural, and national meetings. They aren’t alone. Around the world, government officials and scientists have been struggling for decades to manage nuclear-contaminated forests in ways that minimize radiation exposures for human populations.
Although significant environmental contamination from accidents at reactors and military facilities dates back to the 1950s,3 the dilemma of how to manage contaminated forests emerged most dramatically and most publically after a reactor at the V.I. Lenin Nuclear Power Plant near Chernobyl blew up on 26 April 1986. The accident released a massive amount of radioactive contamination through the western Soviet Union and across northern Europe.4,5 It fell most heavily near the power plant, in a region covered in forests and fields.
The problems the contaminants brought would not disappear quickly. Although radiation from iodine-131 falls by half in just eight days, the half-life of cesium-137 is 30 years; for plutonium-239 it’s 24,100 years. Soviet officials took immediate steps to limit the health impacts of the contamination by removing the region’s residents. Since the 1991 breakup of the Soviet Union, the land has been managed as a protective buffer where trees and other plants help stabilize the contamination within a mostly uninhabited area.
This strategy has become the world’s principal model for handling severe radioactive contamination at the landscape level. For it to work, however, governments must permanently ban people from large areas or accept that those who remain will be exposed to more radiation than the International Commission for Radiological Protection recommends for the general population.6
In contrast, Japan’s current recovery plan revolves around removing contamination from the landscape to allow residents to move back home. In this context, contaminated forests represent not a buffer but a threat to public health.
Still, the question of whether forests can—or should—be cleaned up remains extremely controversial. Two years after the Fukushima disaster, Japan’s government has not yet decided whether it will follow the Chernobyl template for forest management or instead try to create a new model for postnuclear environmental remediation.
Inside the exclusion zone, the central government was directly responsible for overseeing the work; beyond it, local governments managed the process. Soon contractors and ordinary citizens were hosing down, wiping off, and vacuuming up invisible particles from the surfaces of houses, roads, and schools throughout eastern and central Fukushima, while backhoes scraped soil from fields and stripped grass from parks.28 In woodlands near houses, the people raked up leaves and removed lower branches from trees.29
Clockwise from top left: Bags of contaminated soil from Iitate; a tower for monitoring movement of radionuclides in Kawamata; trial decontamination behind a home in Kawauchi; forestry and construction workers join in forest decontamination training at Forest Park Adatara, Otama.
All images: © Winifred A. Bird
The work continues with mixed success. Radioactive cesium can in some cases be washed or wiped off smooth surfaces like tile, but it easily becomes stuck in the crevices of uneven materials and binds strongly to clay. Decontaminating large areas covered in vegetation, such as parks and gardens, usually means removing and disposing of whatever the cesium is stuck to. Grass and weeds, for instance, are cut, not washed, and dirt is usually removed or deep-plowed, according to Kathryn Higley, head of the Department of Nuclear Engineering and Radiation Health Physics at Oregon State University. The process is labor-intensive, expensive, and prone to corner-cutting.30 To make matters worse, rain, wind, animals, and people can move irradiated debris around, recontaminating areas that have already been treated.As the cleanup proceeded, many Fukushima residents interviewed for this story say they began to suspect that forested slopes were a key source of recontamination—although research has not yet proved this.
Japan’s own guidelines for dealing with the contamination called for prioritizing cleanup in places that would most impact human health.39 It was in this context that the ministry committee declared extensive forest decontamination unnecessary.
The backlash from Fukushima was immediate and harsh. One after another, local and prefectural officials and forestry industry representatives attacked the proposal as a city-centric, top-down decision that ignored the deep connections between rural residents and their forested environment as well as the differences between Fukushima and Chernobyl40—in northeast Japan, the topography is steep and complex rather than flat; rain is abundant; and forests are closely entwined with densely populated farmland. Although forests have contained the bulk of the contamination around Chernobyl, many doubted they could—or should—play the same role around Fukushima.