The Water We Drink: Is Plastic Lurking?

Plastic pollution is a pressing environmental issue, with millions of tons of plastic ending up in our oceans each year. The problem of plastic in water is twofold: not only does plastic physically pollute waterways, but its production also consumes a significant amount of water. This water footprint includes the water used in the extraction of oil or natural gas, as well as the water required to reduce thermal pollution from cooling heated water during the manufacturing process. The proliferation of plastic products and our `disposable` lifestyle have contributed to the vast amount of plastic waste in our oceans, with poor waste management practices further exacerbating the problem.

Plastic's water footprint

Plastic has become a ubiquitous part of modern life, with its use increasing year on year. It is a versatile and useful material, but it has a huge environmental footprint, and plastic pollution is everywhere. The environmental impact of plastic is not just limited to the plastic in the water but also includes the water it takes to produce it. This is known as the water footprint of plastic.

The water footprint of plastic includes the water used in production (the blue water footprint) and water pollution (the grey water footprint). Each step in the life cycle of plastic, from the extraction of oil or natural gas to the final product, consumes water. This water is permanently withdrawn from its source and is no longer available for use. The blue water footprint of plastic refers to the water consumed during the drilling, refining, and manufacturing of the oil and natural gas that are the raw materials for plastic. This type of water consumption also includes water that is evaporated and lost to the watershed. The grey water footprint refers to the water required to reduce pollution during production, such as the water needed to reduce thermal pollution from cooling water heated during processing. If the heated water is discharged into waterways, it can harm the environment, so cooling water is added to reduce the temperature of the discharged water.

Polyethylene terephthalate (PET) plastic, the source material of water bottles, soda bottles, and more, makes up 10.2% of global plastic production. A 2011 study estimated the blue water footprint of the "oil to PET" steps to be 2.64 gallons of water per pound (10 litres per kilogram). However, when the grey water footprint is added, the total water footprint jumps to 28 gallons per pound (235 litres per kilogram). This means it takes about 1.4 gallons (5.3 litres) of water to produce a typical single-use water or soda bottle. From 2002 to 2014, approximately 3.83 billion metric tons of PET plastic resin was produced worldwide, equivalent to 29 trillion plastic water bottles. The total blue and grey water footprint for all this PET works out to about 91.8 billion cubic meters, which is enough water to fill 693 billion bathtubs.

With such a large water footprint, it is important to consider ways to reduce plastic consumption and improve plastic production processes to minimise the impact on our planet's finite water resources.

Plastic in the ocean

The presence of plastic in the ocean is a growing problem. While it is difficult to determine the exact amount of plastic in the ocean, it is estimated that about 8 to 10 million metric tons of plastic enter the ocean each year, and the total amount of plastic in the ocean is currently estimated to be about 50-75 trillion pieces of plastic and microplastics. This plastic pollution has devastating impacts on marine life and ecosystems. It causes damage to animals through suffocation, entanglement, laceration, and internal injuries. It is also estimated that by 2050, plastic will likely outweigh all fish in the sea.

Microplastics, which are tiny pieces of broken-down plastic, are a significant concern in the ocean. These microplastics can absorb harmful pollutants like pesticides, dyes, and flame retardants, and later release them into the ocean. Abandoned fishing nets and synthetic clothing are common sources of microplastics. Additionally, microbeads found in some soaps and personal care products contribute to the microplastic pollution in the ocean.

Addressing the issue of plastic in the ocean requires a multi-faceted approach. Reducing plastic use, reusing and recycling plastic items, and properly disposing of waste are essential steps. Participating in cleanup efforts, such as the NOAA's Marine Debris Program, can also help remove plastic from the ocean and prevent further pollution. However, it is important to focus on fixing the broken waste management systems and transitioning to renewable resources to stop the flow of plastic at its source.

The presence of plastic in the ocean is a critical issue that requires collective action from individuals, societies, and global organizations. By increasing awareness, reducing plastic consumption, improving waste management, and advocating for sustainable practices, we can work towards minimizing the impact of plastic on our oceans and ecosystems.

Environmental impact of plastic

Plastic pollution is a pressing environmental issue, with rapidly increasing production of disposable plastic products overwhelming the world's ability to deal with them. The proliferation of plastic products in recent decades has been extraordinary, with humans producing over 380 million tons of plastic annually, and this figure is rising as plastic and oil companies ramp up production. Half of all plastics ever manufactured have been made in the last 20 years, with production increasing exponentially from 2.3 million tons in 1950 to 448 million tons by 2015.

Plastic is a versatile and cheap material, with properties that make it ideal for many applications. However, these qualities have also resulted in it becoming an environmental issue. We have developed a "`disposable' lifestyle, with estimates suggesting that around 50% of plastic is used just once and thrown away. Single-use plastics account for 40% of the plastic produced every year, and these products have a lifespan of just minutes to hours, yet they may persist in the environment for hundreds of years.

The environmental impact of plastic is not limited to plastic in water but also includes the water used to produce it. The water footprint of plastic accounts for the total volume of freshwater consumed in the entire production process. This includes the water consumed in the processes of extracting, refining, and manufacturing the raw materials, as well as the water required to reduce thermal pollution from cooling the water heated during processing. The production of a typical single-use water or soda bottle requires about 1.4 gallons (5.3 liters) of water.

Plastic pollution has a significant impact on aquatic ecosystems, with an estimated 19-23 million tons of plastic waste leaking into lakes, rivers, and seas each year. Major rivers act as conveyor belts, picking up trash as they move downstream and carrying it to the sea. Once at sea, plastic waste is transported by ocean currents around the world. Sunlight, wind, and wave action break down plastic waste into microplastics, which are spread throughout the water column and have been found in every corner of the globe, from Mount Everest to the Mariana Trench. These microplastics are also breaking down further into smaller and smaller pieces, and have been found in municipal drinking water systems, drifting through the air, and in human blood, lungs, and feces. The impact of microplastics on human health is still being studied, but millions of animals are killed by plastics every year, and nearly 2,100 species, including endangered ones, are known to be affected.

Plastic production and consumption

Plastic is a relatively new invention, with the first examples dating back to the late 1800s. However, its versatility, durability, and low production cost have made it one of the most widely used materials today. Plastic production has sharply increased over the last 70 years, with global production surpassing 400 million metric tons in 2022, an annual increase of 1.6%. In 2023, the worldwide production of plastics reached 413.8 million metric tons. Asia is the largest producer of plastics, with China alone accounting for 32% of global production in 2022. North America is the second-largest producer, with a 17% share in 2022.

The proliferation of plastic products has been extraordinary, with an estimated global consumption of 60kg per person per year. However, this average is much higher in Western Europe, where the average annual plastic consumption is around 150kg per person. Over half of the plastic ever manufactured has been produced since 2000, and we are set to double our current global annual production by 2050. The production of plastic requires four basic steps: acquiring raw materials, synthesizing a basic polymer, compounding the polymer into a usable fraction, and molding or shaping the plastic.

The environmental impact of plastic is significant, not only due to plastic waste in the water but also because of the water required to produce it. The water footprint of plastic accounts for the total volume of freshwater consumed in the entire production process. Polyethylene terephthalate (PET) plastic, which is used for water bottles, soda bottles, and more, makes up 10.2% of global plastic production. The water footprint of PET includes the water consumed in extracting, refining, and manufacturing the oil and natural gas that serves as its raw material.

The blue water footprint of PET refers to the water consumed to produce the raw material, which comes from surface or groundwater sources. The grey water footprint refers to the water required to reduce thermal pollution from cooling the water heated during the manufacturing process. The estimated blue water footprint of the "oil to PET" steps was 2.64 gallons of water per pound (10 liters per kilogram). When the grey water footprint is added, the total water footprint jumps to 28 gallons per pound (235 liters per kilogram). This means it takes about 1.4 gallons (5.3 liters) of water to produce a typical single-use water or soda bottle.

Plastic waste is a significant environmental concern, with an estimated 1 to 2 million tons of plastic entering our oceans each year. Some reports indicate that up to 50% of plastic is for single-use purposes, contributing to a "disposable" lifestyle. While some plastic is recycled, incinerated, or stored in sealed landfills, a significant portion is mismanaged, leading to pollution of the environment and oceans. Improving waste management practices, especially in low-to-middle-income countries, is critical to tackling the issue of plastic pollution.

Water used in plastic manufacturing

Water is required for almost every step in the production processes for many raw materials and finished products. This is known as the water footprint of a product, which is calculated by adding up all of the water required for each step of the production process.

The water footprint of plastics includes the water consumed in the processes of extracting, refining and manufacturing crude oil and natural gas, which are the raw materials used to make plastic. It takes about 180 litres of water to produce 1 kg of plastic. This is nearly the amount of water used per capita per day in Kenya (198 litres/inhabitant/day) according to data from 2002. In 2015, 322 million metric tons of plastics were produced worldwide, which corresponds to a total of 1.8 x 10^11 litres of water.

The water footprint of plastics can be divided into the blue water footprint and the grey water footprint. The blue water footprint is the amount of surface water and groundwater required to produce an item. For Polyethylene terephthalate (PET) plastic, which makes up 10.2% of global plastic production, the blue water footprint of the raw material to resin steps was 2.64 gallons of water per pound (10 litres per kilogram). The grey water footprint is the amount of freshwater required to dilute the wastewater generated in manufacturing to maintain water quality standards. The grey water footprint of PET plastic was 28 gallons per pound (235 litres per kilogram). Thus, the total water footprint of PET plastic is 2.64 gallons of water per pound (10 litres per kilogram) for the blue water footprint and 28 gallons per pound (235 litres per kilogram) for the grey water footprint.

The grey water footprint of plastic manufacturing is significant as it makes up the largest portion of the total water footprint of a smartphone, which is another product that contains plastic. The water footprint of the production of a single smartphone is an estimated 3,190 gallons, with each step of smartphone manufacturing, from mining for precious metals to creating synthetic chemicals for glue and plastic, consuming water.

The use of water in plastic manufacturing has substantial environmental ramifications, contributing to the global water crisis and water pollution. Water is also required for recycling plastic, which further increases the water footprint of plastics.

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