当你吃鱼的时候，它的体内可能含有微小的塑料粒子。

你甚至不知道，生活中产生的塑料污染正在进入海洋，并进入了我们食用的鱼类的体内。

那件羊毛外套？你每次洗衣服的时候，微小的塑料纤维就被冲入下水管中。你的牙膏和沐浴液？如果它们含有微粒，这些沙粒状的塑料碎屑也导致了污染。

“废品管理不善后患无穷，会反过来影响我们的饮食，”生态学家切尔西 罗克曼说。“现在，我们在贻贝，牡蛎，蛤，鱼，甚至海盐中都能发现塑料。”

塑料到处都是。它很便宜和方便，但也伴随着越来越高的环境成本。根据罗克曼在加州大学戴维斯分校领导的一项研究，加利福尼亚和印度尼西亚的鱼市中进行采样，大约有四分之一的鱼体内都含有人造垃圾——塑料和纺织纤维。

“在世界各地不同的栖息地，都能发现不同形态和体积的塑料污染，”罗克曼说。 “这包括海滩。包括公海。包括珊瑚礁、海草栖息地，深海，还有我们认为比较偏远的地区，北极冰。”

令人惊讶的来源

然而，消费者可能没有意识到的是，鱼摄入的塑料碎片不仅来自工业活动，垃圾，垃圾填埋场径流和流出的污水，还有来自日常家务生活的部分，如洗衣服。

主要罪魁祸首之一:羊毛夹克

加州大学圣巴巴拉分校的研究人员发现，含有羊毛成分的夹克每次洗涤的时候，平均会释放出1.7克超细纤维，那些旧的、低质量的夹克用洗衣机洗涤时流出的超细纤维量最大，这些超细纤维流向当地的污水处理厂，其中40%进入河流、湖泊和海洋。

为了更好地理解这个问题并提前预防，巴塔哥尼亚委托圣塔巴巴拉分校进行研究，结果表明，洗涤10万件羊毛夹克释放出的超细纤维量相当于1.19万个塑料购物袋。

微粒是另一个塑料污染来源。这些微小的，沙粒状塑料颗粒在家用产品中很常见，经常作为磨砂洗涤剂，包括洗面奶、沐浴露和牙膏。它们的体积太小，在污水处理过程中不能被有效地过滤，目前在水生生物的栖息地和鱼体内都有发现。

根据罗克曼撰写的一份政策简报，每天有数十亿的微粒被排入家用下水管道中。例如，仅在旧金山湾，据估计，每天超过4.71亿的微粒被释放进海湾。

一旦到达海湾，这些微塑料就像海绵一样，吸收海洋中的其他化学物质，增加了它们的毒性。

禁止使用微粒

罗克曼和她的团队参与加利福尼亚和联邦政府颁布的微粒禁令。联邦政府禁止在个人护理产品中使用微粒，美国总统奥巴马在2015年12月签署了这一法律，它将在2017年年中生效。联邦禁令包括在牙膏等洗涤产品中使用微粒，但没有涵盖化妆品或指甲油。

“加利福尼亚法案促进了联邦立法，”罗克曼说。”它也指出微塑料应该作为政府的一个重要课题。该法案有助于人们理解和关心这个问题。”

直到它们被淘汰，消费者可以在选择个人护理产品时，避免选择含有聚乙烯、聚丙烯或尼龙的产品，这是最常见的含有微粒的物质。

对健康的影响

那么，对于我们食用的含有塑料的鱼，我们该怎么办呢？

“我试图限制自己摄入食物链顶端的鱼类，如剑鱼，鲨鱼和金枪鱼，因为当你食用食物链顶端的鱼类时，毒性在放大，”罗克曼说。“但对微塑料，众多的问题仍然存在，那就是海鲜中的塑料如何影响人类健康或它会如何影响鱼类的健康。”

罗克曼在加州大学圣地亚哥分校获得了生物学学士学位，在戴维斯分校获得了生态学博士学位，进行博士后研究，而且目前是多伦多大学的助理教授。她下一步的计划是研究塑料碎片对人类和鱼类健康的影响。

“海鲜是健康食品。它含有人体必需的脂肪酸。我不想吓唬人，让大家不要食用海鲜，”罗克曼说。“但是需要做一下研究，关于鱼体内含有塑料问题，了解是否对人类健康存在一个毒性阈值。”

以下为英文原文：

How plastic ends up in our seafood and what you can do about it

When you eat fish, it may contain tiny pieces of plastic.

And without even knowing it, you may be adding to the plastic pollution that is washing into oceans and winding up in the fish we eat.

That fluffy fleece jacket? Every time you wash it, little bits of plastic fibers are washed down the drain. Your toothpaste and body wash? If they contain microbeads, those tiny sand-like fragments of plastic also are part of the problem.

"The mismanagement of our waste has even come back to haunt us on our dinner plate," said ecologist Chelsea Rochman. "Plastic has now been found in mussels, oysters, clams, fish and even sea salts."

Plastic is everywhere. It's cheap and convenient but comes with a growing environmental cost. Roughly a quarter of the fish sampled from fish markets in California and Indonesia contained human-made debris—plastic and fibers from textiles, according to a study led by Rochman while at UC Davis.

Rochman, one of the first to directly link plastic in the oceans to the fish on our dinner plates, spoke on the subject last week at the Monterey Bay Aquarium Sustainable Foods Institute and at Secretary of State John Kerry's Our Ocean Conference.

"Plastic pollution is found in all shapes and sizes in diverse habitats all over the world," Rochman said. "This includes beaches. It includes the open ocean. It includes coral reefs, seagrass habitats, the deep sea and, often what we consider to be remote, arctic ice."

Surprising sources

What consumers may not realize, however, is that the plastic debris ingested by fish comes not only from industrial activities, litter, landfill runoff and sewage overflows, but from everyday household activities like washing clothes.

One of the primary culprits: Fleece jackets.

UC Santa Barbara researchers have found that synthetic fleece jackets release, on average, 1.7 grams of microfibers each wash, with the most shedding caused by older, lower-quality jackets cleaned in top-load washing machines. These microfibers then travel to your local wastewater treatment plant, where up to 40 percent of them enter into rivers, lakes and oceans.

The amount of microfibers released by laundering 100,000 fleece jackets is equivalent to up to 11,900 plastic grocery bags, according to the UC Santa Barbara study, commissioned by Patagonia to better understand the problem and get ahead of the issue.

Microbeads are another source of plastic pollution. The tiny, sand-like grains of plastic are used in hundreds of household products, often as abrasive scrubbers, including face washes, body washes and toothpaste. They are too small to be efficiently filtered by wastewater treatment processes and have been found in aquatic habitats and fish.

Billions of microbeads are washed down household drains every day. In just the San Francisco Bay estuary, for example, it is estimated that more than 471 million microbeads are released into the bay every single day, according to a policy brief by Rochman.

Once there, the microplastics act as a sponge and soak up other chemicals in the sea, increasing their toxicity.

Banning microbeads

Rochman and her team's work was instrumental in California and federal bans on microbeads. The federal ban on microbeads in personal care products, signed into law by President Obama in December 2015, will begin to take effect in mid-2017. The federal ban covers microbeads in toothpaste and "rinse-off" products, but does not cover those in makeup or nail polish.

"The California bill led to the federal legislation," Rochman said. "It also put microplastics on the map as an important topic to the government. It helped people understand and care about the issue."

Until they are phased out, consumers can take action by avoiding personal care products that contain polyethylene, polypropylene or nylon – the most common materials used in microbeads.

Health impacts

So just how concerned should we be about the plastics we consume in fish?

"I do try to limit my intake of top predators such as swordfish, shark and tuna because toxins magnify as you go up the food chain," Rochman said. "But for microplastics, many questions remain about how plastic in our seafood may impact human health or how it may impact the health of fish stocks."

Rochman, who has a bachelor's degree in biology from UC San Diego and doctorate in ecology from San Diego State and UC Davis, conducted postdoctoral research at UC Davis and the University of Toronto, where she now is an assistant professor. She next plans to study the health impacts of plastic debris on humans and fish.

"Seafood is very healthy. It has essential fatty acids. I would never want to scare anybody away from eating seafood," Rochman said. "Research needs to be done to see if there is a toxic threshold relevant to humans regarding plastic in fish."