科学是如何消除吸入健康风险的

For a quick summary of the fight for clean air over the past century, look out of any office window.

Odds are your view won't be obscured by dangerous smog – or by clouds of cigarette smoke. For much of the past century, that would have been unthinkable.

"Even since just the 1980s, air pollution has fallen dramatically," said Dr. Robert Brook, a professor of cardiovascular medicine at Wayne State University in Detroit. He can see the improvement just by watching the background when movies from that era come on. “这种变化太神奇了. And it happened slowly enough that people don't notice it."

The change came because of an interaction among scientists, the public and their government that continues to this day, 他和其他专家说. The science involves particles with complex names and massive amounts of data, 但利害关系再简单不过了.

很多人都听说过, “你吃什么就是什么," said Brook, 谁从上世纪90年代就开始研究空气污染了. 他的说法是:“你呼吸什么，你就是什么."

Discussions about smoking and air pollution often focus on cancer, asthma and other lung diseases. But what we inhale has a big effect on heart and brain health, too.

We now know that even a few cigarettes a day or exposure to secondhand smoke can sharply increase the risk of heart disease and stroke. Air pollution, meanwhile, 会增加心脏病发作的风险吗, 中风和心血管疾病死亡.

The story of how science came to understand that doesn't begin in the 20th century, said Dr. 桑杰Rajagopalan, chief of cardiovascular medicine and chief academic and scientific officer at the University Hospitals Harrington Heart and Vascular Institute in Cleveland. He's also a professor of medicine and biomedical engineering at Case Western Reserve University.

Rajagopalan, who worked with Brook on some of the first articles about air pollution and heart disease, said that dirty air has been an issue "ever since man discovered fire."

The U.S. 这个故事可以从香烟开始.

Tobacco – which contains the highly addictive substance nicotine and other harmful chemicals – had been grown in the Americas for thousands of years, 但正如Allan M. 勃兰特2007年的《线上电子游戏飞禽走兽》,“技术的结合, 业务操作, 市场营销和不断变化的社会规范改变了美国.S. 变成了一个吸烟的国家. In 1900, American adults smoked an average of 54 cigarettes per person per year. By 1963, that number peaked at an estimated 4,345, according to a 2007 report 也就是现在的美国国家医学院.

随之而来的是肺癌发病率的惊人上升, which spurred innovations in how medical research is done.

Some of the earliest studies on smoking were done in Great Britain by Dr. 理查德·多尔博士. 奥斯汀·布拉德福德山. 他们最初的工作, in 1950, compared 709 people with lung cancer with an equal number of people without cancer. They followed that with a landmark survey of 40,000 doctors. The results, 出版于1956年, showed that deaths from lung cancer and heart disease were related to how much someone smoked.

到1960年，美国心脏协会 ready to say, "the data strongly suggest that heavy cigarette smoking may contribute to or accelerate the development of coronary heart disease or its complications."

烟草业极力制造混乱, so researchers had to build an ironclad case to explain the risks. The U.S. 外科医生的 1964年关于吸烟与健康的报告 did just that. Not only did it declare that smoking was a cause of cancer, but it also helped establish the modern framework for using data from epidemiological surveys to make connections that couldn't come from simply studying cells under a microscope.

The battle between health advocates and tobacco companies was hardly settled then, 但这是一个转折点. 1965年，将近42%的美国人.S. 成年人——包括卫生局局长Dr. 路德·特里都是吸烟者. 根据最新数据，到2021年 疾病控制和预防中心的数据, only 11.5% were.

A pattern of crisis leading to change also unfolded with air pollution.

In 1948, 致命的烟雾在多诺拉形成, Pennsylvania, 造成至少20人死亡，数千人患病. Four years later, the "Great Smog of London" killed as many as 12,000 people.

Those and other events helped drive passage of the Clean Air Act of 1970 in the U.S., which Rajagopalan credited for a "massive" improvement in air quality. Since that law took effect, levels of regulated pollutants have dropped 78%, according to the 环境保护署.

这种模式会在吸二手烟时重演. The first large studies on its dangers appeared in the early 1980s. 到1990年，美国大部分地区都禁止吸烟.S. flights. 在接下来的几年里, many states would pass laws requiring smoke-free workplaces and public places, 包括酒吧和餐馆.

Dr. Stacey Alexeeff, a research scientist and biostatistician at the Kaiser Permanente Northern California Division of Research, 科学家说, 公众和监管机构相互影响. 公众的强烈抗议导致了《线上娱乐电子游戏网站》的出台, the regulations required monitoring to measure pollution, 哪个提供了更多关于健康影响的数据. The findings led to changes in regulations to protect health.

布鲁克说，他自己的作品也遵循了这样的道路. 在90年代中期, he was launching his career just as some of the first work linking air pollution with cardiovascular disease was being done. Legal challenges to new pollution standards led to the need for more research. In 2004, he was able to lead an expert panel in writing an AHA 科学声明 that saw "a strong case that air pollution increases the risk of cardiovascular disease" but also that more research was needed.

By 2010, 他领导了另一个美国心脏协会小组, 这个包括拉贾戈帕兰, that was able to declare that microscopic particles of pollutants known as PM 2.5, or soot, could cause cardiovascular disease and death. 今年2月，环保署宣布 tighter limits on such pollutants, the main sources of which are diesel and car exhaust and coal-fired power plants.

Many things about science and research changed radically over the past century. Thanks to technology, the cycle of science and policy is speeding up, Rajagopalan said. "In every sphere of medicine and public health, the feedback loops are getting faster."

Alexeeff said that researchers today are emphasizing connections between clean air and socioeconomic status. "The question of how do we protect the most vulnerable populations is a really important one," she said.

但当前的一些问题与过去一样. Problems from cigarettes didn't show up until years after masses began using them. Today, the advent of vaping is exposing people to chemicals whose effects are only beginning to be understood.

And just as in the days of the original Clean Air Act and the first studies on smoking, 谈论监管把空气问题变成了一个政治问题. “我不是政治家,拉贾戈帕兰说, but it's a simple fact that elected officials can alter the future of clean air.

For researchers, the biggest issue in that future is climate change.

Rajagopalan has written that higher temperatures boost ozone levels while also increasing risks of wildfires and dust storms, 哪些会产生损害心脏健康的污染物. Researchers also will need to identify the best ways to protect people from such problems – whether it's masks, 空气过滤器或其他东西, Brook said.

他回忆起去年夏天, smoke from Canadian wildfires unexpectedly blanketed Detroit and other portions of the Midwest and East Coast, giving them some of the worst air pollution in the world. Brook drew parallels to the "massive public health catastrophes" of London and Donora that reshaped public opinion.

他说，这将塑造未来. "Nothing's going to happen if the public doesn't demand it."

Brook said he wished people were more aware of just how much their health depended on clean air – and how much better things had gotten.

"Science informs; the bureaucrats can make decisions," he said. "We need to be aware of how much benefit has occurred during just our lifetimes, 这对我们有多重要."