Nature · 人与自然 / 健康 / 科普
微塑料正在"侵入"人脑：尸检研究揭示 8 年间浓度上升约五成
An autopsy study finds plastic particles accumulating in the human brain at levels far higher than in other organs — and rising over time
中文导读
几十年来，科学家追踪微塑料穿越海洋、土壤，甚至进入我们吃下的食物；而一项发表在《自然·医学》上的研究，把目光投向了最意想不到的地方——人脑。由新墨西哥大学毒理学家领导的团队，分析了 52 名逝者的脑、肝、肾组织，结果发现：每一份脑样本中都含有微塑料，其浓度是肝脏和肾脏的 7 至 30 倍；更令人不安的是，2024 年收集的大脑样本，微塑料含量比 2016 年高出约五成。大脑约六成是脂肪，而塑料多为脂溶性，纳米级颗粒或能穿过本应阻挡有害物质的血脑屏障。不过，研究者谨慎地强调：样本量太小，尚无法证明微塑料导致了痴呆等任何具体疾病。本文揭示的，是一个关于"便利代价"的现代之问——在塑料生产不断飙升的今天，我们也许已经无法"置身其外"。
一、原文精读
鼠标悬停在带 蓝色虚线下划线 的生词上，即可查看词性和释义。
🔊 英音朗读 · British English
由英音语音合成（en-GB）朗读全文原文，共 9 段。播放时原文会随进度逐句高亮，建议先盲听抓大意，再对照下方原文跟读，留意重音、连读与停顿。
【1】For decades, scientists have tracked microplastics through the ocean, the soil and even the food we eat. A new study, however, has located them in the place we might least expect: the human brain, where their concentration appears to be climbing with each passing year.
【2】The findings, published in the journal Nature Medicine and led by a toxicologist at the University of New Mexico, examined brain, liver and kidney tissue from 52 people whose organs were donated after death, drawing on samples collected in both 2016 and 2024.
【3】Using a chemical process to dissolve the tissue and leave behind only particles, the researchers identified twelve different types of plastic, then weighed and counted the fragments under an electron microscope — a technique sensitive enough to detect pieces far smaller than the width of a human hair.
【4】The results were unambiguous: every brain sample contained microplastics, and the brain held seven to thirty times more than the liver or kidney. Most striking of all, brains collected in 2024 showed roughly fifty percent more plastic than those from 2016, a rise that mirrors the surging tide of plastic production worldwide.
【5】Why the brain should accumulate so much remains unclear, but the authors offer a compelling explanation. The brain is roughly sixty percent fat, and many plastics are fat-soluble, meaning they slip easily into lipid-rich tissue; the smallest particles, moreover, may cross the blood-brain barrier, the protective membrane that is supposed to keep harmful substances out.
【6】By far the most abundant material was polyethylene, the plastic used in bottles and shopping bags, which turned up as tiny shards and flakes scattered through the tissue. Such particles, the researchers note, are now so widespread that no one — rich or poor, young or old — is likely to be free of them.
【7】The scientists were careful not to overstate their findings. A link between microplastics and dementia has been floated, they observed, but the present study was far too small, and too limited, to prove that the particles cause any specific disease, let alone the conditions that some headlines have implied.
【8】Even so, the study has sharpened an uncomfortable question about the modern world: whether the conveniences of plastic — cheap, durable, everywhere — carry a hidden cost that science is only beginning to measure. As mounting evidence finds the particles in blood, placentas and breast milk, researchers increasingly ask not whether we are exposed, but what that exposure means.
【9】For the public, the message is one of caution rather than alarm. Experts say individuals can reduce their intake by drinking filtered water and avoiding food heated in plastic, yet they stress that real change must come from reducing plastic production itself — a task, they argue, that lies with industry and government, not with the choices of any single person.
原文出处：本文根据《自然·医学》（Nature Medicine，2025 年 2 月）刊发、由新墨西哥大学（University of New Mexico）Matthew Campen 团队完成的尸检研究，及 Scientific American 相关报道（2025-08 综合）整理编写，供学习使用。
三、长难句分析（三步拆解法）
A new study, however, has located them in the place we might least expect: the human brain, where their concentration appears to be climbing with each passing year.
主干：A new study ... has located them in the place（主语 + has located + 宾语 + 地点状语）
定语从句（省略关系代词）：we might least expect（修饰 place，关系代词 that/which 作宾语被省略）
同位语（解释说明）：the human brain（冒号引出，具体说明 place 指哪里）
非限制性定语从句：where their concentration appears to be climbing with each passing year（where 指代 in the human brain）
考点：省略关系代词的定语从句；where 引导非限制性定语从句；appear to do 结构
译文：然而，一项新研究在我们最意想不到的地方——人脑——找到了它们，而且其浓度似乎正逐年攀升。
The findings, published in the journal Nature Medicine and led by a toxicologist at the University of New Mexico, examined brain, liver and kidney tissue from 52 people whose organs were donated after death, drawing on samples collected in both 2016 and 2024.
主干：The findings ... examined brain, liver and kidney tissue from 52 people（主语 + examined + 宾语）
过去分词作后置定语（并列）：published in the journal Nature Medicine and led by a toxicologist ...（修饰 The findings）
定语从句：whose organs were donated after death（whose 修饰 52 people）
现在分词作状语 + 过去分词作定语：drawing on samples collected in both 2016 and 2024（drawing on 表"利用"；collected 修饰 samples）
考点：过去分词作后置定语；whose 定语从句；现在分词作状语；过去分词作定语
译文：这项发表于《自然·医学》杂志、由新墨西哥大学一位毒理学家领导的研究，检测了 52 名死后捐献器官者的脑、肝、肾组织，并利用了分别于 2016 年和 2024 年收集的样本。
The brain is roughly sixty percent fat, and many plastics are fat-soluble, meaning they slip easily into lipid-rich tissue; the smallest particles, moreover, may cross the blood-brain barrier, the protective membrane that is supposed to keep harmful substances out.
并列结构：两个分句由分号连接：The brain is ... fat, and many plastics are fat-soluble；the smallest particles ... may cross the blood-brain barrier
现在分词作状语：meaning they slip easily into lipid-rich tissue（meaning 后接宾语从句，表"意味着"）
同位语 + 定语从句：the protective membrane that is supposed to keep harmful substances out（解释 barrier；that 引导定语从句）
考点：分号连接的并列句；现在分词作状语；同位语；be supposed to do（理应、本应）
译文：大脑约六成是脂肪，而许多塑料是脂溶性的，意味着它们容易进入富含脂质的组织；此外，最小的颗粒或许还能穿过血脑屏障——那道本应把有害物质拒之门外的保护膜。
A link between microplastics and dementia has been floated, they observed, but the present study was far too small, and too limited, to prove that the particles cause any specific disease, let alone the conditions that some headlines have implied.
主干：A link ... has been floated ... but the present study was far too small, and too limited, to prove that ...（but 连接并列句；被动语态）
插入语：they observed（"他们指出"）
宾语从句：that the particles cause any specific disease（作 prove 的宾语）
let alone 结构：let alone the conditions that some headlines have implied（"更不用说……"；内含 that 引导的定语从句修饰 conditions）
考点：too ... to ...（太……而不能）；let alone；插入语；定语从句
译文：他们指出，人们曾提出"微塑料与痴呆之间存在关联"的说法，但本研究规模太小、也过于有限，无法证明这些颗粒会导致任何具体疾病，更不用说某些标题所暗示的那些病症了。
As mounting evidence finds the particles in blood, placentas and breast milk, researchers increasingly ask not whether we are exposed, but what that exposure means.
主干：researchers increasingly ask not whether ..., but what ...（主语 + ask + not ... but ... 并列宾语从句）
时间状语从句：As mounting evidence finds the particles in blood, placentas and breast milk（as 引导，"随着"）
宾语从句（并列）：whether we are exposed（是否暴露）；what that exposure means（这种暴露意味着什么）
考点：not ... but ... 结构；whether 与 what 宾语从句；as 引导时间状语从句
译文：随着越来越多的证据在血液、胎盘和母乳中发现这些颗粒，研究者们愈发追问的已不是"我们是否暴露"，而是"这种暴露意味着什么"。
四、全文大意
几十年来，科学家一直追踪微塑料穿越海洋、土壤乃至食物的轨迹，而一项发表在《自然·医学》上的研究，把目光投向了最意想不到的地方——人脑。由新墨西哥大学毒理学家领导的团队，检测了 52 名死后捐献器官者的脑、肝、肾组织，样本分别来自 2016 年和 2024 年。他们用化学方法溶解组织、只留下颗粒，在电子显微镜下识别出 12 种塑料。结果毫不含糊：每一份脑样本都含有微塑料，且大脑中的含量是肝脏和肾脏的 7 至 30 倍；最令人震撼的是，2024 年收集的大脑样本，微塑料含量比 2016 年高出约五成，这一上升趋势正与全球塑料生产的汹涌浪潮相呼应。至于大脑为何累积如此之多，作者给出了一种有说服力的解释：大脑约六成是脂肪，而许多塑料是脂溶性的，容易进入富含脂质的组织；此外，最小的纳米级颗粒或许还能穿过本应阻挡有害物质的血脑屏障。研究中最常见的塑料是聚乙烯——瓶子和购物袋所用的材料，它以微小碎片和薄片的形式散布在组织中；研究者指出，这些颗粒如今已无处不在，无论贫富长幼，恐怕无人能幸免。不过，科学家们谨慎地避免夸大结论：虽然有人提出微塑料与痴呆之间的关联，但本研究样本量太小、过于有限，无法证明颗粒会导致任何具体疾病，更不用说某些新闻标题所暗示的病症。即便如此，这项研究仍然尖锐地提出了一个关于现代世界的尴尬之问：塑料"便宜、耐用、无处不在"的便利，是否藏着科学才刚刚开始测量的隐性代价？随着越来越多的证据在血液、胎盘和母乳中发现这些颗粒，研究者追问的已不是"我们是否暴露"，而是"暴露意味着什么"。对公众而言，这一信息是"谨慎"而非"恐慌"：个人可以通过饮用过滤水、避免用塑料容器加热食物来减少摄入，但专家强调，真正的改变必须来自减少塑料生产本身——而这，是产业与政府的责任，而非任何个人选择所能左右。
五、思考与仿写
思考题：结合第 5、7 段，为什么研究者一方面说"大脑为何累积这么多仍不清楚"，另一方面又强调"无法证明微塑料导致任何具体疾病"？这体现了科学研究怎样严谨的态度？
仿写题：仿照第 8 段 "researchers increasingly ask not whether we are exposed, but what that exposure means."（not whether …, but what … 的并列宾语从句）的句式，围绕「环保」「健康生活」或「坚持学习」写一个句子。