Human Interactions with the Environment Part II

Production of waste and pollutants:

With the ever-increasing population, the consumption of resources has escalated over the years. Due to the mass consumption of resources, it is inevitable that massive wastes are produced all across the globe. According to the report of of Environment, Forests and Climate Change (MoEF&CC),

Urban India (about 377 million people) generates 62 million tonnes of municipal solid waste each year, of this about 43 million tonnes (70%) is collected and 11.9 million tonnes (20%) is treated.

About 31 million tonnes (50%) is dumped in landfill sites (Fig. 1). With changing consumption patterns and rapid economic growth it is estimated that urban municipal solid waste generation will increase to 165 million tonnes in 2030. In India, open defecation and inadequate sanitation have also contributed to adverse effects on human health as well as the environment. Waterborne diseases are caused by pathogens (disease-causing agents) in water and food that have been contaminated by the wastes from infected people. Preventing this connection between human wastes and the intake of contaminated water is a major challenge for the government authorities in India.

Fig 1. A mountain of trash in Ghazipur landfill site, Delhi Industry, agriculture and energy production all generate wastes that can pollute air, water and soil.

Pollution means the introduction into the environment of substances liable to cause harm to humans and other living organisms. For example, the leather industry produces large amounts of liquid wastes from the tanning process. These wastes contain organic materials such as fat from the hides and toxic (poisonous) chemicals including some human carcinogens (cancer-causing agents).

Another example is the release of so-called greenhouse gases such as carbon dioxide, methane and nitrous oxide, which contribute to human-induced climate change. Figure 2 summarises the interactions between ‘human activities’ and ‘the environment’. The green arrow indicates the waste generated as a product of this interaction. The red arrows indicate the negative effect on both the environment and humans if the waste is not properly managed.

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Fig 2 Human–environment interaction and the generation of waste and pollutants. Technology and the environment

Technologies have transformed transport, industry, communications and our lives at home and work. For instance, gadgets such as mobile phones, computers, televisions, microwave ovens and refrigerators have improved living standards for those people who can afford them. Technology can also improve the quality of our environment. For example, energy can be generated from renewable sources such as wind and solar power, which reduces our reliance on non-renewable energy sources such as fossil fuels, and also helps to reduce the release of polluting gases to the atmosphere.

Another example of the benefits from technology is the highly advanced eco-friendly wastewater treatment plants. These plants recover nutrients and waste water from the industries that would otherwise be released into the environment. This type of technology can help to alleviate the problem of water shortage, prevent surface water pollution and protect the environment. In India,

Prof S.A. Abbasi from Pondicherry University has designed a bio-reactor which uses the water hyacinth to absorb nutrients, pathogens and microorganisms from water. Grey water or domestic sewage from 38 houses is fed into the plant which measures around 9 meters by 2 meters, and has a capacity of 10,000 litres (Fig 3).

Fig 3. Eco-friendly wastewater treatment Plant, Pondicherry Although technology has many positive impacts on people and the environment, it also has negative impacts, including the production of toxic waste from technological processes and electronic gadgets that are thrown away when they reach the end of their useful lives, as illustrated in Fig 4.

When electronic equipment or gadgets get old or stop working they are often thrown away. This type of electronic waste is referred to as e-waste. E-wastes pose a huge challenge to the environment because they contain toxic substances such as cadmium and lead from batteries, which leach out and pollute rivers and groundwater. (Leaching means the substances seep out or are washed out by rain into the soil below.) Toxic substances may get into the soil, making it unfit for agriculture. Copper from wiring is valuable for recycling, but if wiring is burned, it produces very hazardous air pollution.

Fig 4. Uncontrolled E-Waste Disposal in Mumbai

E-waste is becoming a major problem in many developing countries, including India, where the use of electrical equipment has increased sharply with the rising number of people on higher incomes.

According to a United Nations University report, the world generated 44.7 million tonnes of electronic waste in 2016 - equivalent to the weight of some 4,500 Eiffel Towers. India’s contribution to this was a significant 2 million tonnes. As there is no proper e-waste management system in India, some e-wastes are disposed of together with other household wastes or dumped in an uncontrolled way that may cause huge environmental problems. Figure 5 shows open solid waste disposal sites in Ghaziabad close to residential areas. All types of waste, including hazardous waste like heavy metals, are discarded here without any treatment, so toxins can seep into the soil and groundwater. (Hazardous waste is any waste that contains material that is potentially harmful, for example, toxic, infectious, corrosive, explosive or flammable materials.)

Fig 5. Solid waste disposal site in Indirapuram, Ghaziabad

Agriculture and environment

Agriculture sector is very important in India to provide essential food crops and as a source of income, contributing about 15.4 % of country’s Gross Domestic Product (GDP). About 47% of the labour force in India is in the agricultural sector, so it is vital to the livelihoods of the majority of people. However, agriculture also has significant negative impacts on our environment, including loss of biodiversity, pollution, climate change, soil erosion and the use of large amounts of water for irrigation. Agricultural activities are also major sources of water pollution. Pesticides and fertilisers applied to crops may wash into rivers and leach into soil and groundwater.

Poor farming practices, especially on steeply sloping land, are a significant cause of soil erosion in the mountainous areas in India, since rainfall washes away the soil particles downhill. This lost soil is not only a problem for agriculture, it silts up rivers and lakes. Soil erosion and loss of soil biodiversity causes a decline in soil fertility and this in turn reduces agricultural productivity.

Efficient agricultural practices, such as the use of terraces and diversion ditches, can help stop soil being lost from hillsides (Fig 6).

Fig 6 Efficient agricultural practices such as building terraces on sloping land helps to conserve

soil.

Agriculture also plays a role in causing climate change through the release of greenhouse gases into the atmosphere. For example, fertilisers added to the soil release nitrous oxide and livestock production releases methane from the digestion process in cattle and the decomposition of manure.

The use of fossil fuels to power agricultural machines and burning trees to clear agricultural land both release carbon dioxide. How we can protect and restore our environment:

It is important to note that humans not only affect the environment negatively - we can also contribute positively to sustain it. Installation of wastewater treatment plants protect endangered species and replant forests, which have a positive impact on our environment. Since 2000, huge efforts have been made in India to increase the forest coverage through government and NGO reforestation programmes. According to a NASA report, China and India have led in increasing the

Earth's greenery over the past two decades. In 1950 around 40.48 million hectares was covered by forest in India. In 1980 it increased to 67.47 million hectares and in 2006 it was found to be 69 million hectares.

Fig 7. Volunteers at a Miyawaki forest plantation drive in Bengaluru

Many parts of the country where the reforestation programme has been implemented effectively, the community has already started to benefit from environmental improvements, through effects such as creating more spring water, a higher water table, and less soil erosion and flooding. Besides, effective enforcement of environmental laws and regulations is crucial for proper environmental management.