ENVIRONMENTAL POLLUTION

Pollution is the introduction of contaminants into the natural environment that cause adverse change.^[1] Pollution can take the form of chemical substances or energy, such as noise, heat or light. Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Pollution is often classed as point source or nonpoint source pollution.

Ancient cultures

Air pollution has always accompanied civilizations. Pollution started from the prehistoric times when man created the first fires. According to a 1983 article in the journal Science, "soot found on ceilings of prehistoric caves provides ample evidence of the high levels of pollution that was associated with inadequate ventilation of open fires."^[2] The forging of metals appears to be a key turning point in the creation of significant air pollution levels outside the home. Core samples of glaciers in Greenland indicate increases in pollution associated with Greek, Roman and Chinese metal production,^[3] but at that time the pollution was comparatively less and could be handled by nature.

Official acknowledgement

King Edward I of England banned the burning of sea-coal by proclamation in London in 1272, after its smoke became a problem.^[4]^[5] But the fuel was so common in England that this earliest of names for it was acquired because it could be carted away from some shores by the wheelbarrow. Air pollution would continue to be a problem in England, especially later during the industrial revolution, and extending into the recent past with the Great Smog of 1952. London also recorded one of the earlier extreme cases of water quality problems with the Great Stink on the Thames of 1858, which led to construction of the London sewerage system soon afterward.
It was the industrial revolution that gave birth to environmental pollution as we know it today. The emergence of great factories and consumption of immense quantities of coal and other fossil fuels gave rise to unprecedented air pollution and the large volume of industrial chemical discharges added to the growing load of untreated human waste. Chicago and Cincinnati were the first two American cities to enact laws ensuring cleaner air in 1881. Other cities followed around the country until early in the 20th century, when the short lived Office of Air Pollution was created under the Department of the Interior. Extreme smog events were experienced by the cities of Los Angeles and Donora, Pennsylvania in the late 1940s, serving as another public reminder.^[6]

Modern awareness

Pollution became a popular issue after World War II, due to radioactive fallout from atomic warfare and testing. Then a non-nuclear event, The Great Smog of 1952 in London, killed at least 4000 people.^[7] This prompted some of the first major modern environmental legislation, The Clean Air Act of 1956.
Pollution began to draw major public attention in the United States between the mid-1950s and early 1970s, when Congress passed the Noise Control Act, the Clean Air Act, the Clean Water Act and the National Environmental Policy Act.^[8]

Smog Pollution in Taiwan

Severe incidents of pollution helped increase consciousness. PCB dumping in the Hudson River resulted in a ban by the EPA on consumption of its fish in 1974. Long-term dioxin contamination at Love Canal starting in 1947 became a national news story in 1978 and led to the Superfund legislation of 1980. Legal proceedings in the 1990s helped bring to light hexavalent chromium releases in California—the champions of whose victims became famous. The pollution of industrial land gave rise to the name brownfield, a term now common in city planning.
The development of nuclear science introduced radioactive contamination, which can remain lethally radioactive for hundreds of thousands of years. Lake Karachay, named by the Worldwatch Institute as the "most polluted spot" on earth, served as a disposal site for the Soviet Union throughout the 1950s and 1960s. Second place may go to the area of Chelyabinsk U.S.S.R. (see reference below) as the "Most polluted place on the planet". ^[9]
Nuclear weapons continued to be tested in the Cold War, sometimes near inhabited areas, especially in the earlier stages of their development. The toll on the worst-affected populations and the growth since then in understanding about the critical threat to human health posed by radioactivity has also been a prohibitive complication associated with nuclear power. Though extreme care is practiced in that industry, the potential for disaster suggested by incidents such as those at Three Mile Island and Chernobyl pose a lingering specter of public mistrust. One legacy of nuclear testing before most forms were banned has been significantly raised levels of background radiation.^{[citation needed]}
International catastrophes such as the wreck of the Amoco Cadiz oil tanker off the coast of Brittany in 1978 and the Bhopal disaster in 1984 have demonstrated the universality of such events and the scale on which efforts to address them needed to engage. The borderless nature of atmosphere and oceans inevitably resulted in the implication of pollution on a planetary level with the issue of global warming. Most recently the term persistent organic pollutant (POP) has come to describe a group of chemicals such as PBDEs and PFCs among others. Though their effects remain somewhat less well understood owing to a lack of experimental data, they have been detected in various ecological habitats far removed from industrial activity such as the Arctic, demonstrating diffusion and bioaccumulation after only a relatively brief period of widespread use.
A much more recently discovered problem is the Great Pacific Garbage Patch, a huge concentration of plastics, chemical sludge and other debris which has been collected into a large area of the Pacific Ocean by the North Pacific Gyre. This is a less well known pollution problem than the others described above, but nonetheless has multiple and serious consequences such as increasing wildlife mortality, the spread of invasive species and human ingestion of toxic chemicals. Organizations such as 5 Gyres have researched the pollution and, along with artists like Marina DeBris, are working toward publicizing the issue.
Growing evidence of local and global pollution and an increasingly informed public over time have given rise to environmentalism and the environmental movement, which generally seek to limit human impact on the environment.

Forms of pollution

The Lachine Canal in Montreal Canada, is polluted.

The major forms of pollution are listed below along with the particular contaminant relevant to each of them:

Air pollution:- the release of chemicals and particulates into the atmosphere. Common gaseous pollutants include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight. Particulate matter, or fine dust is characterized by their micrometre size PM₁₀ to PM_2.5.

Light pollution:- includes light trespass, over-illumination and astronomical interference.
Littering:- the criminal throwing of inappropriate man-made objects, unremoved, onto public and private properties.
Noise pollution:- which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar.
Soil contamination occurs when chemicals are released by spill or underground leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE,^[10] herbicides, pesticides and chlorinated hydrocarbons.
Radioactive contamination, resulting from 20th century activities in atomic physics, such as nuclear power generation and nuclear weapons research, manufacture and deployment. (See alpha emitters and actinides in the environment.)
Thermal pollution, is a temperature change in natural water bodies caused by human influence, such as use of water as coolant in a power plant.
Visual pollution, which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of trash, municipal solid waste or space debris.

Water pollution, by the discharge of wastewater from commercial and industrial waste (intentionally or through spills) into surface waters; discharges of untreated domestic sewage, and chemical contaminants, such as chlorine, from treated sewage; release of waste and contaminants into surface runoff flowing to surface waters (including urban runoff and agricultural runoff, which may contain chemical fertilizers and pesticides); waste disposal and leaching into groundwater; eutrophication and littering.

Earth pollution

Types of earth pollution

Pollution

Clouds of choking smog; beaches coated in oil; rivers turned red by chemicals. All of these are obvious examples of pollution.

However, not all types of pollution are easily seen. For example, invisible plumes of gas may drift over our towns and cities. They can cause asthma and chest problems. They can also kill trees.

Another problem is finding out the size of the area affected. Winds can blow pollutants across thousands of kilometres, from one side of an ocean to the other. Chemicals flowing down large rivers can pollute many countries on their way to the sea.

Then there is the problem of finding out who is to blame.

Satellites are key weapons in this never-ending fight to keep the planet clean. Space-based instruments can detect harmful gases and chemical waste released by industry, power plants and traffic.

Satellites can pinpoint the sources of pollution, watch it move through the air and see where it ends up. They can also study ocean colour and detect oil spills at sea, both day and night.

For example, diseases related to air pollutants are diabetes, cardiac failure and cardiac ischemic events, lung cancer, and asthma. There are many studies currently assessing the effects of pollutants on human diseases.
Are doctors trained to look for the symptoms of chemical poisoning?
The study of clinical toxicology is a post-graduate medical course. The training is still available from specific post-graduate organizations. However, the training takes around three years, and isn’t as popular as other post-graduate courses. Undergraduate medical courses will be lip service at best, as most undergraduate curriculum is already quite condensed as it is.
How persistent are the toxins?
It’s dependent on the type of toxins; some radioactive substances like uranium have different long half-lives depending on the isotope.
Another factor in humans is the ability to clear the toxins from the body; there are large genetic variations in the ability to clear toxins depending on the effectiveness of the metallothionein system in each individual. The nutritional factors that contribute to this clearance are also dependent on the how healthy a diet the person adopts.
Toxins can access the human body via three main routes: What we eat, drink and breathe. Other exposures depend on specific circumstances. For example, if a worker is exposed to a specific toxin at work and keeps getting re-exposed on a daily basis, then the body burden and persistence will be high. For example, in the past, when many miners were exposed to asbestos, the long term accumulation led to asbestosis many decades down the line, and some [miners] went on to develop mesothelioma, a form of cancer affecting the lining of the lung. But the delay between the exposure and onset was separated by many decades, and it took a while to decipher the cause-and-effect relationship.
Today, we have evidence of newborns having some 200-plus chemical toxins in their cord blood; these can only come from the persistence of these chemicals from the mother, and through the placental circulation over the nine month in utero period.
I truly believe that this persistency will cause epigenetic issues and affect health adversely. Not every chemical will be removed from this baby in its lifetime, especially if awareness is not forthcoming. The persistence of these toxins in the environment has been extensively studied.
What evidence do you have that the toxins can persist for three generations?
The data comes mainly from epigenetic and genomic studies about trans-generational toxic effects.
A brief analogy: If you consider the cord blood study, you can appreciate that the 200-plus chemical toxins in the cord blood can only be contributed by the mother via placenta blood circulation—hence two generations. Now what are the chances that all of these toxins will be cleared by all ten babies before they become parents? (Another generation.) Now think where the toxins of the mother that gave birth to the tested baby may come from? (Her own mother would be a likely contributing source—another generation.)
You've called the lack of action on this issue "inexplicable." But what do you think is going on? Why have governments and health care professionals been slow to act on this? Is it just incompetence, or are there wider issues?
In one word: funding. There is truly a lack of funding and appreciation of global pollutants affecting diseases. Most funding has been directed towards remediation of polluted sites and environmental research by scientists, not clinicians.
The key issue that has contributed to the lack of action or understanding in the past has been the time lag between the cause and effect of specific toxins. The Agency for Toxic Substances and Disease Registry (ATSDR) has mentioned delays of around 10 to 40 years for the onset of diseases.
In the current age, however, there is really no excuse for not being aware of the issues of toxicity and the contributions these have to diseases. Unfortunately, most undergraduates and post-graduates in medicine have never been taught about these matters, and as such are quite alienated from the available data. Many chronic diseases in our current society are not satisfactorily managed, and addressing the issues of toxic burden together with currently known factors will certainly contribute to better standards of management.
At the national and global level, the US EPA and the WHO do recognize the importance of toxic chemicals and their impact on diseases. However, this knowledge has been slow in adoption into clinical practice. I guess I’m in favor of giving the benefit of the doubt to patients in circumstances where the question of toxicity arises, and chronic diseases have not responded to routine measures, because of my qualifications and awareness of these issues. However, in routine practices, I feel many cases are missed on a daily basis, and in the light of our current knowledge and understanding of health impacts due to pollutants, this is most unfortunate.

Via Wikimedia

What action would we need to take to begin reversing the situation?
Managing the body's toxic burden is a preventative medicine issue in the main. Of course, there are cases of acute and chronic toxicity that are managed in emergency situations and in clinical practices as well.
All humans from birth to tomb have some degree of pollutants in their internal environment, and are also exposed to pollutants in the external environment. Christopher Wild has proposed the concept of the Exposome. This is the sum of exposures from all sources.