Land pollution is more commonly known as soil contamination. This is a seriously underestimated type of pollution because we usually focus more on air pollution and water pollution. We live on land and spend all our lives on land and hence we take it for granted. A clean surface to walk on or unpolluted soil to grow things in will become important after the first two priorities of land and water have been met. But, soil contamination is just also a big problem in the long run and hence it is needed to pay more attention to it.
Soil Pollutants:
The land area is severely limited and useful land even less. Though in this era of modernization and city living, the need for arable land is decreasing, still arable land holds great importance for the places where we grow our food.
The most arable land is what humans first settled on and then these settlements turned into big cities. The proof of this is that, if we look out for most of the largest metropolitan cities in the world, they are usually next to some freshwater source, commonly a river or a stream that carries nutrients fit for farming. These cities, which in ancient history used to be counted as greenery are now concrete jungles with little to no farming activity being done within the city limits. Instead, food is being transported from to cities from various other places, involving energy consumption to skyrocket. If all cities were built like Las Vegas on arid land, then arable land would have not been wasted and the arid land waiting for it to be used would have been utilized.
Farming
As we depend more on farms being productive and growing more and more food we have to get better at preventing crop failures and wastage of food at the production source. Farmers need to eke every last grain or kernel out of their farms to continue to be profitable, and this means turning to chemistry to artificially boost their production. This is done by using fertilizers to make the soil as nutrient-rich as possible and thus raise the yield. Another way is to spray pesticides and herbicides to kill off animals and plants that can kill crops.
The result is the dousing of land with more and more chemicals that strain it to the limit. Within our cities also, we use pesticides and herbicides in excess as no one wants to see a weed growing through a crack in the pavement, or rats and cockroaches running around cities, so large areas are doused with these chemicals all the time. This makes sure that any life the land had in it is exterminated, including healthy organisms such as earthworms and snails. There are insecticides that also all eventually find their way into the soil. Underground animals move the soil around, water seepage carries the chemicals around too, and basically, it all spreads to surrounding areas as well. Intensive farming also causes the land to not be allowed to breathe and rest between crop cycles, which is not a sustainable practice.
Industry
Another cause of pollution is the industries. When something is produced, it has waste material and other non useful by-products. This can range from easily disposable organic waste to some deadly chemicals that have to be handled professionally. Some waste is even radioactive, such as nuclear waste from weapons programs, reactors and even the medical industry.
There are waste products produced in every industrial process and disposal of those wastes is a lot easier to monitor for larger factories. For small or micro-businesses, these disposal norms might not be easy to enforce.
Sometimes the pollution occurs due to an accident, or a spill, rather than on purpose, and even if those people are taken to task for their negligence, it doesn’t change or reverse the negative effect on the soil at the accident site.
Mining
A mine can decimate an environment. Mines are a messy business and the sheer amount of digging and earth moving causes an upheaval of the entire area.
Let’s take a common example of coal mining. A lot of coal mining is done as strip mining — where the entire surface is stripped away to get to the coal deposit. Strip mining devastates the site at which it is done because the entire topsoil is removed. And it’s not just flat land that is being stripped, but entire mountains have disappeared because coal was found inside them. Coal mining is a massive undertaking and forests and plants are stripped away to make way for the huge equipment that’s needed to mine it, as well as transport whatever is mined. This deforestation then results in erosion when it rains, and that alters the land permanently. That’s not all because mining also relies on digging up all of the soil and rocks to get at the coal, but this means that a lot of other toxic elements and compounds that were buried are now exposed to the surface. This can include mercury arsenic selenium and also coal dust, which can react with other elements to form toxic compounds when exposed to the weather All of these can poison the surrounding land making it arid and desolate.
Landfills
Landfills are basically, a large community dumping ground, far away from residential areas, where waste is taken and usually buried. It’s estimated that global solid waste from cities totals over 2 billion tonnes a year. While it’s true that developed countries account for more than their fair share of this waste generation, they’re also the ones that sort, recycle and compost the maximum percentages as well. The world bank estimated that high-income countries account for just 16 per cent of the population, but generate 34 per cent of the world’s waste. However, those same countries also collect well over 90 per cent of generated waste, with much less than 10 per cent going directly into the environment uncontrolled. In comparison, India’s waste generation is about 277 million tonnes a year, and a majority of that, 77 per cent is dumped in open dumps, 18 per cent is composted and only 5 per cent is recycled.
The problem is not all landfills are equal. When waste decomposes, it produces many gases, especially methane, which is very harmful to the environment. One way to avoid dealing with trapped methane or other such gases is to keep it in an open landfill, which is what most of our landfills are. More sophisticated waste management can have landfills where these gases are collected from underground in a controlled manner, isolated and then used for chemical purposes in industries.
The problem with open landfills is that there s a lot of trash lying on the surface and the production of gases and liquids due to the decomposition of the waste can result in fires. When millions of tones of trash burn it can set off other chemical reactions which produce even more toxic and harmful byproducts than simple decomposition would. And of course, the land nearby water bodies and the surrounding air is polluted.
However, not all landfills are bad. Green waste and food waste is especially suitable for landfills because organisms can break them down easily and are generally safe. The process of composting helps to enrich the soil instead of damaging it. If you mix plastics and green waste or food waste it means someone down the line has to separate them, and if it is done improperly the process is contaminated itself. This results in less being recycled, and more landfills are filled with stuff that will not degrade and thus harm the soil, Microplastics in the soil can change the composition of the soil and affect how the soil holds water. But that’s not all, if there is plastic inside a composting dump that plastic is shredded in the process and ends up contaminating the fertilizer that’s produced. Nutrients and microplastics alike are absorbed into the plants, and we end up with our fruit and vegetables containing more and more microplastics.
We need to wake up and pay a lot more attention to this underestimated pollution and to the way we are treating our environment.