日本福島核災事件後食品輻射風險比較分析之研究

Abstract

2011年3月11日，日本外海發生規模重大的地震，導致福島第一核電廠設備嚴重受損，並釋放出大量放射性物質，進而對周遭土地與海洋造成嚴重汙染。除了對環境產生嚴重影響外，這場災害也引起了國際社會的高度關切。為確保台灣國民的健康與安全，自2011年3月25日起，台灣即刻暫停接收來自日本福島、茨城、櫪木、群馬和千葉等五縣所生產的食品。同時，台灣政府也強化了對從日本進口食品的輻射檢測措施，並在邊境進行進口產品的輻射水平檢驗。這一系列的防護措施旨在確保食品的安全性，並保障國內市民的健康。 福島核災事件發生已逾10年，各國正逐漸放寬或部分開放對日本食品的進口。從科學研究的角度來看，自2011年起，日本厚生勞動省開始對全國範圍內的農產品、飲用水、野生動物肉類、畜產品、水產品、牛乳以及嬰兒食品等相關項目進行輻射劑量的監測。根據2018年、2019年和2020年的監測報告，共有584件流通中產品檢測出微量輻射，另外有38件產品超過了衛生福利部食品藥物管理署所公告的標準（Cs-134 + Cs-137的標準如下：飲用水和包裝水10 Bq/Kg；乳製品和嬰兒食品50 Bq/Kg；其他食品100 Bq/Kg），違規比率約為0.116%。這些超標產品主要分布在福島、群馬、茨城、新潟、宮城、長野、岩手以及山形等八個縣。超標的38件產品包括農產品中的蕈類共23件、五加科植物10件（包括漉油和遼東楤木芽）、蕨類1件，以及其他類別中的蕈類加工品3件和米製品1件。 根據2019年國人平均攝食資料，我們將人口分為孩童（0-12歲）、青少年（13-18歲）、成人（19-64歲）、老年人（≥65歲）以及育齡女性（15-49歲）這五個年齡層。我們計算了因攝食2020年從日本進口的17大類食品（A.全穀雜糧類、B.乾豆堅果類、C.油脂類、D.家禽類及其製品類、E.家畜類及其製品類、F.魚、水產類、G.蛋類、H.乳品類、I.水果類、J.蔬菜類、K.糖及糖果零食類、L.飲料類、M.酒類、N.調味料類、O.複合食品、湯品及其他類、P.嬰幼兒食品、Q.保健食品類）所引起的輻射暴露量。我們發現這些暴露量遠低於國際輻射防護組織建議的非背景輻射的游離輻射年劑量不超過1毫西弗的標準。 具體而言，根據我們的計算，不同年齡層在攝取上述食品後，其癌症增加風險均非常低。在不同年度間，癌症的風險呈現相對穩定的趨勢，並且這些風險皆低於台灣整體癌症發生率。此外，對於不同年齡層的輻射暴露量和癌症風險進行觀察，我們可以發現儘管成年人攝取食物量較大且輻射暴露較高，但整體而言，青少年是需要特別關注的群體。在癌症風險方面，青少年可能面臨著較高的潛在風險。

On March 11, 2011, a significant earthquake struck off the coast of Japan, leading to severe damage to the Fukushima Daiichi nuclear power plant and the release of a substantial amount of radioactive materials, resulting in extensive contamination of the surrounding land and ocean. Besides causing severe environmental impacts, this disaster also triggered high levels of international concern. To ensure the health and safety of the Taiwanese population, Taiwan immediately suspended the import of food products from five prefectures in Japan—Fukushima, Ibaraki, Tochigi, Gunma, and Chiba—starting from March 25, 2011. Simultaneously, the Taiwanese government reinforced radiation testing measures for imported Japanese food products and implemented radiation level inspections at the borders. These comprehensive protective measures were designed to ensure the safety of food items and safeguard the well-being of the domestic populace. Over a decade has passed since the Fukushima nuclear disaster, and countries are gradually easing restrictions or partially reopening their doors to Japanese food imports. From a scientific standpoint, Japan's Ministry of Health, Labour, and Welfare began monitoring radiation doses in various items such as agricultural products, drinking water, wild animal meats, livestock products, seafood, milk, and baby food across the nation since 2011. According to monitoring reports from 2018, 2019, and 2020, a total of 584 products in circulation showed trace amounts of radiation, and an additional 38 products exceeded the standards set by Taiwan's Ministry of Health and Welfare for Cs-134 and Cs-137 (standards: 10 Bq/Kg for drinking water and packaged water; 50 Bq/Kg for dairy and baby food; 100 Bq/Kg for other food items). The violation rate stood at around 0.116%. The non-compliant products were primarily found in eight prefectures: Fukushima, Gunma, Ibaraki, Niigata, Miyagi, Nagano, Iwate, and Yamagata. Among the 38 products that exceeded the standards, 23 were mushroom products from agricultural sources, 10 were from the Araliaceae family (including Cyclocarya paliurus and Eleutherococcus senticosus), 1 was a fern, 3 were processed mushroom products from other categories, and 1 was a rice product. Using 2019 average dietary intake data, the Taiwanese population was categorized into five age groups: children (0-12 years), adolescents (13-18 years), adults (19-64 years), elderly individuals (≥65 years), and reproductive-age females (15-49 years). We calculated the radiation exposure resulting from the consumption of the 17 major food categories imported from Japan in 2020 (A. Cereal and Grain Products, B. Legumes and Nuts, C. Fats and Oils, D. Poultry and Poultry Products, E. Livestock and Livestock Products, F. Fish and Seafood, G. Eggs, H. Dairy Products, I. Fruits, J. Vegetables, K. Sugar and Confectionery, L. Beverages, M. Alcoholic Beverages, N. Seasonings, O. Composite Foods, Soups, and Other Categories, P. Infant and Toddler Foods, Q. Health Foods). We found that these exposure levels were significantly lower than the recommended annual dose of non-background ionizing radiation of 1 millisievert by the International Commission on Radiological Protection. Specifically, based on our calculations, the cancer risk associated with food consumption for different age groups was found to be very low. The estimated annual average cancer risk was 1.00 x 10^-7 for children, 1.32 x 10^-7 for adolescents, 1.18 x 10^-7 for adults, 1.01 x 10^-7 for elderly individuals, and 9.80 x 10^-8 for reproductive-age females. These data indicate that the cancer risks for these age groups are lower than Taiwan's overall cancer incidence rate.