Who isn’t familiar with pollution?
But there are many aspects of these that we do not know.
I am providing a short primer here.
When we think of land pollution, we usually visualize a lot of junk, overflowing landfills and plastics. But land pollution goes far beyond these.
While we mostly associate pollution with waste disposal – as this is what is right in front of us – the rest of the pollution sources are as widespread as, and probably result in more harm than, pollution from waste disposal alone.
The primary reasons for land pollution are:
- Waste disposal – domestic and industrial waste (including hazardous waste), and animal and human waste too!
- Agricultural chemicals
The use of agricultural chemicals (especially pesticides) in fields could result in our cereals, fruits and vegetables actually carrying a bit of the toxins present in the pesticide along with them – and we end up eating these. In fact, this danger has been one of the key motivators for the organic food movement.
While in many cases the polluting effects of mining are indeed restricted to the communities nearby, it is not always. In some cases, a good lot of nasty chemicals get drained into the rivers nearby, and the harmful effects of these could thus carry hundreds of kilometers down the river.
As you can see, the effects of land pollution, if unchecked can be quite widespread and devastating.
For sure, solutions are being attempted. What kind of solutions?
- To deal with problems such as waste disposal, some effective solutions already exist. We know that recycling can dramatically reduce the need for sending waste to landfills; recycling also reduces the need for incineration, a process that might not always be clean and environment-friendly.
- We’ll need stuff like mines for a long time to come. In some countries however, it’s now commonplace to require mine operators to clean-up mines and restore the landscape after they’ve finished working them – sometimes mine owners even have to file financial bonds to ensure they have the money in place to do this. But this doesn’t happen always!
- Greater interest in organic food and farming might, one day, lead to a reduction in the use of harmful agricultural chemicals, though we are unlikely to see significant reductions anytime soon. Even so, public concerns about food and chemical safety have led to the withdrawal of the more harmful pesticides—in some countries, at least.
All these things offer hope for a better future—a future where we value the environment more, damage the land less.
All these also, in many ways, can use a variety of cleantech solutions – some of these already available, and some being designed and developed.
What comes to your mind when you think of water pollution? Mainly the dirt and pollution you can see in lakes, rivers and oceans. And in the drains!
When we think of Earth’s water resources, we think of oceans, lakes, rivers, drains. Water resources like these are called surface waters. The most obvious type of water pollution affects surface waters – be it a large oil spill, or some amounts of plastic from the neighbouring locality.
Not all of Earth’s water sits on its surface, however. A great deal of water is held in underground rock structures known as aquifers, which we cannot see and hence seldom think about. Water stored underground in aquifers is known as groundwater. Aquifers feed our rivers and supply much of our drinking water. They too can become polluted, for example, when weed killers used in people’s gardens or in agricultural farms drain into the ground, or when chemicals leach into the ground from waste landfills. Groundwater pollution is much less obvious than surface-water pollution, but is no less of a problem – and sometimes can pose a bigger danger than surface-water pollution.
Thus, surface waters and groundwater are the two types of water resources that pollution affects. There are also two different ways in which such pollution can occur – from a point, concentrated source (for instance, a factory), or from different scattered, non-point sources (for instance, multiple sewer lines that drain into a river).
Causes of water pollution
Many human activities have an effect on the quality of our water environment. When farmers fertilize the fields, the chemicals they use are gradually washed by rain into the groundwater or surface waters nearby. Sometimes the causes of water pollution are quite surprising – for instance, in what is called atmospheric deposition, chemicals released by chimneys can enter the atmosphere and then fall back to earth as rain, entering seas, rivers, and lakes and causing water pollution.
Broadly, some of the prominent water pollution aspects are the following:
- Sewage – The stuff from our washrooms and toilets
- Nutrients – Mainly from the agricultural sector’s using of fertilizers
- Waste water – This could be from domestic or industrial sources, and the industrial sources could have a whole lot of diverse waste within them.
- Chemicals washed down drains and discharged from factories – This could include super hazardous pollution from the release of heavy metals, such as lead, cadmium, and mercury.
- Radioactive waste – This is not as widespread as others and usually occur from concentrated sources. The biggest sources of radioactive pollution in Europe for instance are two factories that reprocess waste fuel from nuclear power plants.
- Oil pollution – These could come from tanker accidents (though this is only about 10% of total), and from routine shipping and from the oil people pour down drains on land. However, what makes tanker spills so destructive is the sheer quantity of oil they release in one very localized part of the marine environment.
- Plastics – Who has not seen plastic wash up on sea shores! This happens because, in addition to our heavy use of plastic and its indiscriminate disposal, most plastics are not biodegradable – they do not break down naturally in the environment – and so survive in the marine environment for a long time. (A plastic bottle can survive an estimated 500 years in the ocean, far, far longer than the human being who had originally disposed it!). Plastics present a major hazard to seabirds, fish, and other marine creatures.
Similar to the case of land pollution, a number of solutions are being tried out to remediate water pollution. Not all of these can be classified as clean technologies. For instance, a good number of chemicals are used in waste water treatment in effluent treatment plants in industries – and not all of them are harmless.
At the same time, a parallel industry for water pollution and waste water treatment is emerging that use more sustainable technologies. An example of this is in the increased interest in using algae as a remediation agent for at least some portions of the waste water treatment both for industrial and domestic sectors.
You can see that, while the developed world is doing fairly well, many developing countries especially appear to be in the danger zone – specifically, most cities in China seem are in the Red list.
Air pollution takes mainly two forms
- Visible air pollution, and
- Invisible air pollution
There are two main types of pollutants
- Primarily air pollutants – pollutants that are directly emitted by specific sources. A classic example of a primary pollutant would be the sulfur-dioxide emitted from factories
- Secondary air pollutants – Ones that are owing to the reactions of primary pollutants. Smog created by the interactions of several primary pollutants is an example of a secondary air pollutant.
Prominent causes of air pollution
- Burning of Fossil Fuels: Sulfur dioxide emitted from combustion of like coal, petroleum and other fuels is an important cause of air pollution (this is apart from CO2 that all these processes release!). Pollution from transport vehicles (trucks, jeeps, cars, trains, airplanes) is another main cause for air pollution – these release, in addition to CO2, pollutants such as Carbon Monoxide and Nitrogen Oxides,.
- Exhaust from Factories and Industries: Manufacturing and process industries release large amounts of CO2, carbon monoxide, hydrocarbons, organic compounds, and chemicals into the air.
- Mining Operations: During the mining process, dust and chemicals are released. A number of incidents have been reported where such pollution has severely affected the health of the mining workers, as well as those residing nearby.
- Indoor Air Pollution: Household cleaning products, painting supplies emit toxic chemicals in the air and cause air pollution
Effects of Air Pollution
Some of the effects of air pollution are fairly well known to us:
- Respiratory and heart problems
- Global warming
- Acid rain
But there are many other effects that are much less known:
- Eutrophication: Eutrophication is a condition where high amounts of nitrogen water (a result of washing off the fertilizers into rivers) results in a huge algae bloom. This bloom can kill off the fish, plants and animal species in that location.
- Effect on Wildlife: Animals too need clean air! Toxic chemicals present in the air can force wildlife species to move to new place and change their habitat. Some of these pollutants can also land up subsequently in water and end up affecting animals and fish that live in water too.
- Depletion of Ozone layer: The ozone in earth’s stratosphere is responsible for protecting us from harmful ultraviolet (UV) rays in the sunlight. Chemicals such as chlorofluorocarbons and hydro chlorofluorocarbons are causing a depletion of this layer, resulting in an increasing amount of harmful UV rays on earth. High UV can result in ailments to skin and eyes, besides their possible harmful effects on plants.
Similar to efforts against land and water pollution, significant efforts are being undertaken to curb air pollution too. But with our economic and industrial development growing at a hectic pace worldwide, many have started wondering whether the current efforts are enough to make a big enough reduction. A related concern is whether the solutions being attempted are sustainable enough, or whether they will end up creating new environmental and ecosystem problems.
This is where – once again – the use of clean technologies comes in, for sustainably tackling air pollution.