我觉得这集应该到外面做 I think we should do this one outside.
好多了 这里真漂亮 This is better. This is beautiful.
噢 当然 除了这个 Argh! Gah! Of course... except for this!
垃圾... 是一种污染 Litter... is a kind of pollution.
我希望这罐子不在这儿 But like barely. Like, I would rather it not be here, and it makes me
这东西让我有点生气 它把景色弄难看了 kind of angry and it makes nature less pretty.
但从环境角度来看 即便这里有上百万只铝罐 But, environmentally, there's a pretty low chance that this can,
也只有很小的几率 or even a million more like it, is going to have
对生态系统有显着的负面影响 a significant negative impact on an ecosystem.
我们真正需要担心的污染 The kind of pollution that we really have to worry about
是看不到的那种. is the kind that we don't see.
可能因为他们隐形了，要不就是他们躲在了 Either because it's invisible, or because it's being done in places
我们不太可能碰到的地方 better way out of the way that we're less likely to encounter.
当然 是故意这么设计的, 因为当人们真正看到 That's by design of course, because when people actually see
他们的生活方式对这个世界造成的影响 the impacts that their lifestyle can have on the world,
人们会试着改变生活方式 they tend to sometimes change the way that they live...
以及购物习惯. 但我们看不到这些影响 and also the way that they buy. And we can't have that!
所以，是时候看看这些隐形的污染了 So it's time to get our hands dirty.
"污染"是一个包罗万象的词 Pollution is a kind of catch-all term for any substance that's
是指那些在错误的地方出现的物质或物质浓度 in the wrong place or in the wrong concentrations in the environment.
常见的垃圾，那是污染，但化学物质， Trash in the environment, that's pollution, but chemicals,
自然或人工合成的化学物质，才是真正的杀手。 both naturally-occurring and synthetic, those are the real killers.
现在，我们试着把污染这个术语当作 Now, we tend to think of pollution in terms of weird synthetic
化工厂制造的奇怪的人工合成化学品就对了。 chemicals made in big chemical processing plants,
这就肯定有问题了 and they're certainly a problem.
但就像待会要看到的，你得明白 But as we'll see in a bit, you gotta understand
就算是天然化合物，如果浓度不对 that natural compounds in the wrong concentrations can do
他们的危害和哪些什么杀虫剂等石油衍生品有同样的危害 just as much damage as whatever petro-insecticides we're making.
改变天然化合物浓度的主要途径之一 One of the main ways we're altering concentrations
是生物地球化学循环 of natural compounds is by messing with the biogeochemical
我们几个星期前讨论过了 cycles that we talked about a couple of weeks ago.
你可能都听烦了 但我们搞砸的 You're probably tired of hearing about it, but the most obvious
最明显的循环 是碳循环 cycle we're screwing up is the carbon cycle, which shuffles
碳循环即为，碳元素在各个存储库里移动: carbon around the planet into various reservoirs:
大气层 海洋 石头 以及生物的身体. the atmosphere, the oceans, rocks and the bodies of living things.
谢天谢地 这个循环还在正常运转 但我们把它弄超载了 The cycle keeps going on, thankfully, but we're overloading it
因为我们整天开采煤炭, 石油和天然气 by digging up all that carbon-rich coal, oil and gas
然后靠着它们来过着21世纪的日子 and burning it to fuel our 21st century lifestyles.
突然间，有很多碳被释放了出来 All of a sudden there's more carbon getting released
超出了自然界的处理能力，那些植物和动物就会说 than the reservoirs can handle: Plants and animals are like,
"够了够了，这么多碳已经足够我们用了" "We're cool, got all the carbon we need,"
大海也会说 "是啊 我这边也够了!" the oceans are like, "Yeah, we're good on carbon too!,"
碳没法回石头里去, 所以它就在大气层游荡着 and it can't just go back into the rock, so it hangs around
成了温室气体 in the atmosphere as a greenhouse gas,
隔热了我们的星球 改变了气候 insulating our planet and changing the climate.
我们也把氮和磷循环 We've also been tampering with the nitrogen and phosphorus cycles
起到了类似的影响 to similar effect.
氮和磷是营养物质, 我们和其他生物都需要它 Nitrogen and phosphorous are nutrients, which we and other organisms
而且是非常需要 有了它 我们才能生长 呼吸和 存在 need, like, really need, in order to grow and respire and, exist.
但当我们制造了大量的营养素 然后排给大自然时 But when we go and make like, ludicrous amounts
生态系统会变得混乱了 of these nutrients available, ecosystems get very confused.
就像我五年级的时候 把零用钱全拿去 It's like the day in fifth grade that I realized I could spend
在沃尔格林店 买万圣节后打折促销的吉百利奶油蛋 my entire allowance on Cadbury Cream Eggs
在沃尔格林店 买万圣节后打折促销的吉百利奶油蛋 at the after-Easter candy sale at Walgreens.
一开始很有趣 后面就不是了 It was fun at first... then it was not.
磷酸盐和硝酸盐是化肥的主要成分 Phosphates and nitrates are basically the main ingredients in
某些洗涤剂中也有磷酸盐 fertilizers, and phosphates are also found in some detergents.
因此，当由家庭废水和农田地表径流混合的污水 So when waste water from our houses runoff from farms washes
排入河流和小溪时 会使得藻类大量繁殖, those compounds into rivers and streams, it can cause huge
会造成其他的植物和动物的缺氧 algal blooms that choke out the rest of the plants and animals
还把河流的外观变得很恶心 in the stream and it's totally gross looking.
但这还没完 But that's not the end of it.
当所有磷和氮被用完, 藻类就会死亡 When all the phosphorus and nitrogen are used up, the algae die,
细菌开始分解死掉的藻类 and then bacteria get started on decomposing that dead algae.
当然 分解需要氧气 所以细菌会吸取水里的氧气 But of course the decomposers need oxygen, which they take
然后水的含氧量暴跌 out of the water, and then oxygen levels in the water plummet,
这会让所有的鱼，以及需要氧气的生物都毙命 killing all the fish and just about everything else
这会让所有的鱼，以及需要氧气的生物都毙命 that needs oxygen.
这就是磷和氮会导致"死亡区"的原因 This is how phosphate and nitrate pollution causes dead zones.
最近发生了一件最大条的典型例子 The biggest example of this happening right this very minute
在墨西哥湾的密西西比河口 is in the Gulf of Mexico at the mouth of the Mississippi River.
那里形成了一个占地 18,000 平方千米的死亡区 The Gulf of Mexico Dead Zone covers 18,000 square kilometers
那是由化肥造成的 of river delta and coastline, and is basically a swath
一大片完全无氧的水 of totally deoxygenated water caused by all the fertilizers
这些化肥是来自密西西比河流域的 from the entire Mississippi River basin, which drains
260万平方公里的土地, 2.6 million square kilometers of land,
最终都从墨西哥湾排放了出去 draining to this one point in the Gulf.
死亡区的面积大小会有季节性波动 The size of the dead zone fluctuates seasonally,
因为要看这占了美国一半农场面积的农田施用了多少化肥 as it depends on how much fertilizer is being used
因为要看这占了美国一半农场面积的农田施用了多少化肥 by pretty much half of the farms in America.
所以, 是的. 污染不只是人工合成的化合物 So, yeah. Pollution isn't just synthetic compounds
不只是那些名字有17个字的合成物 with like 17-syllable-long names.
有时候, 他们只是我们需要的，调节体内营养平衡的化合物 Sometimes they're just imbalance of chemicals that we need
有时候, 他们只是我们需要的，调节体内营养平衡的化合物 for our survival.
然而, 不是自然界中的所有化学物质都对我们有好处 However, not all chemicals found in Nature are good for us,
事实上 地球母亲身上也有一些 in fact, sweet old Mother Earth comes up with some
非常毒的东西 of the most toxic stuff that you've ever heard of.
比如 氰化物 Take cyanide, for instance.
我们每天接触的很多东西里都有它的身影 It's in a lot of stuff that we come in contact with every day:
比如杏仁, 菠菜, 青豆 Foods like almonds, spinach and lima beans contain cyanide, and so do the
苹果种子, 桃子种子 seeds of apples, which you have heard, and the pits of peaches.
氰化物对植物很有用, 因为它是原始杀虫剂: Cyanide is useful to plants because it's a primitive insecticide:
它能让虫子细胞中的某种分子窒息 causing a sort of molecular asphyxiation, preventing a bug's
它能让虫子细胞中的某种分子窒息 cells from being able to use oxygen.
致死人类的氰化物含量 比杏仁里的那点要多得多 Now, it takes a lot more cyanide than you'd find in an almond
但你知道吗? to finish off a human, but guess what!
我们找到了可以在一个地方收集大量氰化物的方法! We figured out how to collect a whole bunch of cyanide in one place!
因为我们真的很喜欢黄金! Because we really love gold!
黄金! 我的宝贝! Gold! My precious!
采矿作业大量用到了氰化物 Mining operations use cyanide in large quantities in order to
因为它们需要从矿石中分离金, 银 和其他贵重金属 separate gold, silver and other precious metals from the ore.
分离金属需要喷洒氰化物溶液 In the cyanide process of ore extraction, ground-up ore
它会融化金属 is sprayed with a cyanide solution, which dissolves the metal
金属会留在溶液里 in the ore and draws it out.
之后它们会收集溶液 把贵金属提取出来 The solution is then collected and the precious metal is taken out.
这过程中的副产品 当然 是一大堆 But the byproduct of all this is, of course, a big pile of
掺有氰化物的石头粉末, 又名"危险废物" 我们需要处理它 cyanide-laced rock powder, aka hazardous waste, to deal with.
或至少试着处理一下 Or try to deal with anyway.
它们会用各种方法尽力的去降低 Mines do all kinds of stuff to reduce the concentration
这些废物里的氰化物含量, 最后剩下的叫做"尾矿" of the cyanide in these leftovers, called tailings,
或者他们会尝试把氰化物 转化成毒性较低的氰酸盐 or they try and convert the cyanide into less-toxic cyanate,
但无论如何毒素都是没法完全消除的 but the toxin is never totally eliminated.
它可能会泄漏到地下水里 So then it can end up leaking into the groundwater supply,
或者是呆在原地 继续溶解矿石里面的其他有毒金属 or it can just sit there and keep dissolving other toxic metals
比如汞 ， 然后一起流入我们的水源 out of the rock that also end up in our water, like mercury.
汞是另一种重要的污染物 And mercury is another important pollutant,
它毒性很强 天然的存在于煤矿和一些其他地方 it's a super-toxic, naturally-occurring metal found in coal,
它毒性很强 天然的存在于煤矿和一些其他地方 among other places.
它在地下煤层的时候 就没有什么危险 And it's just fine when it's hanging out underground in a coal seam,
但当我们烧煤发电时 but when that coal is burned to make electricity,
汞会被释放到空气中 the mercury is released into the air.
然后汞会落在地面 进入地下水 And then the mercury falls on the land, where it makes its way
并最终进入到食物链 into groundwater and eventually into the food chain,
尤其是进入海洋食物链 especially into the marine food chain.
美国发电厂和工厂释放出来的汞 As a result, only about 25% of the mercury released by
只有大概25%会留在美国 U.S. power plants and factories actually ends up in the U. S.
其他的会到达世界其他地方 The rest enters the global cycle, which most people end up
最后因吃鱼被人类摄入 ingesting by eating fish.
在动物中 汞是强大的神经毒素 And mercury acts as a powerful neurotoxin in animals,
它会干扰我们的大脑 和神经系统 interfering with our brains and our nervous system.
最后两种我们一直在释放的化合物 Finally, two more naturally-occurring compounds that we keep
是二氧化硫 和二氧化氮 pumping out are sulfur dioxide and nitrogen dioxide.
这些东西最常见的天然来源 是火山爆发 The most common natural sources of these things are volcanic
或是某些藻类和细菌的代谢产物 eruptions, or the waste of some algae and bacteria.
但如今 因为我们燃烧煤炭等化石燃料 But, we release millions of tons of these things
导致每年都有上百万吨的这类物质 被释放到环境中 into the environment every year by burning fossil fuels like coal.
当这些化合物和大气里的水滴互相作用时 And when these compounds react with
当这些化合物和大气里的水滴互相作用时 water vapor in the atmosphere,
会变成硫酸和硝酸 they turn into sulfuric acid and nitric acid,
以酸雨的形式从天上落下 and then return to the surface as acid rain.
在土地上 这些酸会侵蚀出土壤中的其他天然有毒元素 In soils, these acids can cause the release of natural,
比如铝 but toxic, elements like aluminum.
在水中 它们会毒害水生动物 In water, they can poison aquatic wildlife, and on land, the acidity
在陆地上 它们会导致动物卵不能孵化 还能造成植物无法获取养分 can cause animals' eggs to not hatch and plants to lose nutrients.
现在 这类事情已经显着好转了 Now, things have gotten significantly better
因为很多国家正在控制排放 since a lot of countries put emissions controls into place,
但以前 1980年的时候 but for a while there, back in 1980 ,
北美大部分地区的降雨 和番茄汁的pH值相同 rain in much of North America had the same pH as tomato juice.
客观地讲 这是很严重的 Which, objectively speaking, is the grossest.
以上就是我们如何把自然存在的化学物质 So. That's how we're amping up the levels of
升级为有毒物质的故事了 naturally-occurring chemicals to toxic levels.
但当然 我们也合成了大自然 But, of course, we're also synthesizing chemicals
做梦都没想过的化学品 that Mother Nature never even dreamed of.
它们还有其特别的破坏功能 And they wreak their own special brand of havoc.
我们选一种化学品来举例子吧 The problem here is choosing just one as an example, because there
因为实在有太多化学品了 它们破坏的能力还不一样 are so many chemicals out there, doing so many different things.
有一类化学品 称为 内分泌干扰物(EDC) There's a whole class of chemicals called endocrine disruptors,
我们把这类东西放入了药品, 杀虫剂和塑料里 which we put in pharmaceuticals, pesticides and plastics, but some
但有些内分泌干扰物 只是工业和农业生产中的副产品 of them are also just by products of industry and agriculture.
比如 双酚A 缩写是 BPA Endocrine disruptors, like bisphenol A or BPA
最近几年 婴儿奶瓶制造商都争先恐后地 which baby bottle manufacturers have been scrambling to take out
从它们的产品里去除这种化学品 of their products in recent years, hang out
塑料里的双酚A会渗入我们的饮料 in plastics and leach into our drinks
渗滤到我们的饮用水源或流入农田 or are flushed off agricultural fields
或河流，抑或在我们嘘嘘的时候被排到马桶中 and into rivers or are just flushed down toilets when we pee
因为我们服用的某些药物里也有它 them out because they're in some drug that we've been taking.
结果是它们会进入河流里 有时浓度还很高 The result is that they get into waterways, sometimes in high
在那儿生活的动物可就遭殃了 concentrations, and the animals there, they just soak 'em all in.
内分泌系统 基本上就是你的荷尔蒙 The endocrine system, basically just your hormones,
控制着大量的身体功能 controls a vast array of an organism's functions,
随着 内分泌干扰物（EDC） 的浓度增加 and as concentrations of EDC have increased, we've spotted
世界各地河流的雄鱼长出了雌性生殖道 male fish in rivers all over the world with female reproductive
或是睾丸开始生产卵子 tracts or testes that make eggs.
这些鱼生活在水里, 但我们... 我们也会喝到那些水 Those fish are living in the water, but we... we're drinking it.
所有年龄段的人都很容易受到 内分泌干扰物（EDC） 影响 People of all ages are susceptible to EDC
但研究表明 风险最大的是胎儿和婴儿 but research suggests that those most at risk are fetuses and
因为他们的器官和免疫系统还没完全形发育 infants, because their organ and immune systems are still forming.
科学家们仍在研究这些化合物对我们的发育, 生殖, Scientists are still studying the developmental, reproductive,
和神经系统方面的影响 and neurological effects that these compounds are having on us.
就我而已 我觉得它们做得还不够快 And as far as I'm concerned they can't do it fast enough.
人类制造的化学物质会影响哪些方面 我们可以猜 So, the chemicals we're making are affecting us in ways we could
但总有我们做梦也想不到的地方 guess, and also probably ways that we've never even dreamed of.
此外 我们还重新安排了 At the same time, we're rearranging where and how much
天然化合物出现的位置和数量 some naturally occurring compounds are showing up.
这些得加到我们上周谈到的5个影响里 And that adds to those 5 other impacts that we're having on the
是的 最近的两周挺让人失望的 biosphere, and yeah, the past two weeks have been a real bummer.
但希望这些内容能启发到你 But hopefully an enlightening bummer.
这会带领我们到达生态学的下一个阶段 But this leads us to the next stage of ecology, and the last lesson
在这个过程中, 保护生物学和恢复生态学 in this course, Conservation biology and restoration ecology,
共同构成一门足以拯救地球的科学 which together comprise the science of saving our planet,
从我们自己手里... 拯救我们自己 and ourselves from... ourselves.
感谢收看本集速成班生态学 Thank you for watching this episode of Crash Course Ecology.
感谢所有帮忙制作节目的人 And thanks to everyone who helped us put it together.
如果你要复习我们讨论的任何东西 If you want to review any of the stuff that we covered this episode,
这边有张表 there's a table of contents over there that you can click on,