第2285期:Are Microplastics Harmful?

Extremely small pieces of plastic called microplastics are in the ocean and the air, as well as in our food and water. Scientific study has discovered microplastics in human body tissues also, including the heart, liver and kidneys.  极其微小的塑料碎片，被称为微塑料，存在于海洋和空气中，以及我们的食物和水中。科学研究还发现，微塑料存在于人体组织中，包括心脏、肝脏和肾脏。Some researchers worry that microplastics harm human health, although they say that science has not found clear evidence of that. Still, they say questions remain about the possible health effects of microplastics.  一些研究人员担心微塑料会损害人类健康，尽管他们表示科学尚未找到明确的证据。尽管如此，他们认为微塑料对健康的潜在影响仍然存在疑问。Manufacturers mostly use oil or other petroleum products to make plastic. The material is used to make a huge number of different products: water bottles, car parts, children’s playthings, clothing, electronics and more. Heat, weather, and even animal digestion break down plastic into smaller and smaller pieces.  制造商主要使用石油或其他石油产品来制造塑料。塑料材料被用来制造大量不同的产品：水瓶、汽车零件、儿童玩具、衣物、电子产品等。热量、天气，甚至是动物的消化作用都会将塑料分解成越来越小的碎片。Microplastics can be 5 millimeters long at most or as small as one micrometer. A micrometer is one-one thousandth of a millimeter. Microplastics have been found in salt, sugar, honey, rice and seafood. They have also been found in milk, soil, and drinking water.  微塑料最大可以达到5毫米长，也可以小到1微米。1微米是千分之一毫米。人们在盐、糖、蜂蜜、大米和海鲜中都发现了微塑料。它们还被发现存在于牛奶、土壤和饮用水中。Researchers disagree about how much plastic people might be breathing in or taking in as food and drink. Still, many studies find evidence of plastics in body tissues.  研究人员对人们可能通过呼吸或食物和饮料摄入多少塑料存在分歧。尽管如此，许多研究发现了塑料存在于人体组织中的证据。Tracey Woodruff is a researcher at the University of California at San Francisco. She said, “Microplastics have been measured in pretty much all of the body tissues that have been evaluated.”  特蕾西·伍德拉夫是加利福尼亚大学旧金山分校的研究员。她说：“几乎所有被评估的身体组织中都检测到了微塑料。”Scientists are still trying to answer the question of how harmful microplastics might be. In 2022, a World Health Organization report found no clear risk to human health, based on the available evidence.  科学家们仍在试图回答微塑料可能有多大危害的问题。2022年，世界卫生组织的一份报告基于现有证据发现，对人类健康没有明确的风险。There is also not clear evidence of widespread public health effects.  目前也没有明确证据表明微塑料对公共健康产生了广泛的影响。However, researchers only recently began to measure plastic levels in the human body and learn about their possible effects. Woodruff of U.C. San Francisco said it makes sense that microplastics are harmful because they contain poisonous chemicals. The researcher was part of an investigative team that examined nearly 2,000 studies about microplastics at the request of California state lawmakers.  然而，研究人员只是最近才开始测量人体内的塑料水平并了解其可能的影响。加州大学旧金山分校的伍德拉夫表示，微塑料是有害的，这是有道理的，因为它们含有有毒化学物质。这位研究员是一个调查小组的成员，该小组应加利福尼亚州立法者的要求，审查了近2000项关于微塑料的研究。Some evidence suggests plastics can increase inflammation and other changes in the body. Such changes could increase the risk of heart attack and stroke.  一些证据表明，塑料会增加体内炎症和其他变化。这些变化可能会增加心脏病发作和中风的风险。Researchers say there are ways to reduce possible contact with microplastics.  研究人员表示，有一些方法可以减少与微塑料的接触。Take off your shoes before you go into your home. This helps prevent the spread of microplastics inside. Eat foods — especially fresh fruits and vegetables — that you prepare at home. Do not heat foods in plastic containers, Woodruff said. And, she added, use metal or glass water bottles, instead of plastic.  在进入家中之前脱掉鞋子，这有助于防止微塑料在室内传播。吃自己在家准备的食物，尤其是新鲜水果和蔬菜。伍德拉夫说，不要在塑料容器中加热食物。此外，她还建议，使用金属或玻璃水瓶，而不是塑料的。