How is one study on air pollution from 1993 changed history?


In the 1970s, London could become a distant memory. The last great smog occurred in 1962 and it seemed that the problems of air pollution in cities in the UK were resolved. World Leading Council for Air Pollution with Medical Research at London Hospital St. Bartholomew's was closed. In the eyes of the government she did her job. There simply was no need for that.

At the same time as the United Kingdom filled in research capacity, in the United States, Doug Dockery and his colleagues prepared a new type of study to address the effects of air pollution on health. When it was completed and published nearly twenty years later, Dockery's revolutionary findings changed our perspective of air pollution even deeper than the London smog of 1952.

Dockery did not start as a doctor or a healthcare professional. His first degree was physics, and then gradually, through meteorology and environmental science, he moved to study how the environment around us affects our health. Dockery and his team worked at the Harvard Public Health School in Boston. Founded in 1913 to train public health professionals, the work of the school influenced the lives of all of us around the world. They started with infectious diseases; their researchers invented iron lungs to maintain the victims of childhood paralysis before a vaccine was recognized in the 1950s, which was recognized by the Nobel Prize. They also eradicated black goats. In the same way as these achievements, the school can also indicate the work of Dockery and his team, which began with a study of Six Cities.

Since 1974, the Six Cities study included 8111 people randomly selected at six selected locations. These were Watertown in Massachusetts, parts of St. Louisa, the steel city of Steubenville in Ohio, and the less polluted cities of Portage in Wisconsin, Harriman in Tennessee and Topeka in Kansas. The participants filled out questionnaires on their weight, height, smoking, occupational profession and history. Everybody tested his breathing. Each year, the Dockery team sent a postcard to everybody to determine whether they are still dead. If there was no answer, they were sent to the investigator to talk to family, friends and neighbors in order to find out what happened. It took sixteen years. At that time, 1,930 participants died. There was nothing unusual in this, but it was important who died, and what is important, where they lived. Residents of Steubenville and St. Louis died more quickly than those in Topeka and Portage. Compensation for the number of smokers, body mass index and other factors affecting human health have been achieved, but there are still differences between the places that could not be explained. When these differences were plotted against pollution of particles in each site, an extraordinary pattern emerged.

Get your mind back to the lab experiments you did at school and the results you've typed into the graph. There would always be some awkward points that were not perfectly appropriate. You expect the sixteen-year experiment to contain many variables and anomalies, but the team has discovered a nearly equilibrium ratio, which has become one of the most famous surfaces in the science of air pollution. Below is supplemented with the use of original data from the Dockery team.

Due to the additional air pollution that they breathed through traffic and industry around them, people in Steubenville died almost 30 percent faster than people in Portage. And people were not just dying because of lung problems, but, like those in the London smog of 1952, also because of heart problems. This was not strictly the first study to show that everyday exposure to modern air pollution is harmful to our health, while other studies were less clear in their findings.

The publication of the Six Cities study in 1993 was followed quickly by another who looked at the mortality rates in a large group of US citizens who were accompanying them to check the development of cancer. They also died early because of the pollution of particles that they breathed. Suddenly, we realized that the impact of modern air pollution on health is greater than anyone imagined. Even if we look at the purest of six cities, the effect of air pollution is still clear. Our air had to be cleaner; cleaner than air in Portage. New efforts were needed, not only in traditionally polluted areas, such as the Steubenville Steel City, but everywhere.

New pollution laws would be needed to protect human health and establish air standards in our cities. It was clear that industry and vehicle manufacturers, to name only two sectors, will have to do a lot more to clean the pollution they have caused. But, as Arie Jan Haagen-Smith found out forty years ago, interests would fight teeth and nails.

The publication of the six-place study in 1993 received polemics and discussion. Similar to the issues of 21st century climate change and European acid rain problems from the 1970s, those who did not like the results were in doubt. How can Dockery be sure that particle contamination was what made people die early? People breathed a whole lot of air pollutants, not just one. (Honestly, other pollutant studies were measured in a study of six sites, but their correlation with mortality was not nearly as clear.) The Dockery team could not measure all possible pollutants, but what about pollutants that were not measured? Can one of them be the cause? The particles in each site came from very different sources and had different chemical compositions, how could everyone produce the same effect? The association is not the same as the cause; just because people in more polluted cities died earlier did not mean that air pollution actually causes their death. * Can the difference in the mortality rate be due to some other differences between cities? were there differences in weather or the number of people who smoked? Did the researchers simply make a mistake? How could small amounts of particles in the air cause people trouble? Was it really the mass of these particles in the air or their number? If the government were not completely convinced, it should not unduly hurt the profits of the company. Less pronounced in these discussions were the voices that emphasized that some people in these cities were killing people and that immediate action should be taken. Delay would mean that many people die prematurely.

One solution would be to re-conduct six studies to prove this for the second time. But it would take at least sixteen years, plus a time for analysis, in which the industry could do much more than before. The American Congress was involved and it was decided that a separate and independent group of researchers should review the data with the tooth comb and repeat the original work. Lastly, in 2000, the original findings were confirmed. Everyday contamination of the particles we breathe was, and it is still, the shortening of our lives.

The Six Cities study has spurred another evolutionary step in air management. From the approach of the 50s to the management of resources, we have switched to new air pollution laws that set standards for the air itself. Standards and constraints have been created in the United States and Europe, and guidelines have been set by the World Health Organization.

The impact of the study of six sites did not stop. Between 1990 and 1998, a further 1.394 died from the original 8.111 people. In memory of controversy from the original study, the researchers returned to all survivors to discuss with them, to weigh them up and get to know their current health and smoking. Again, an equal link was found between survival and particulate contamination, but this time there were also better news. In the nineties, measures to improve air pollution have begun. Over the course of all sixteen years, particulate pollution has decreased, and the biggest improvements have been observed in the most polluted cities. In Steubenville and St. In Louis, solid particulate contamination in 1998 was less than two-thirds of the level measured twenty years ago. At the other end of the scale, Portage and Topeka showed little or no improvement. Where air pollution has improved, the survival rate has also improved. (The researchers found a similar result when the six-place survivor was re-examined in 2009.) Air purification was working and at least some of the harmful effects on health were reversible.


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