Environmental and human costs of leather - and what the future of leather looks like

A worker moves between the dye pools at the Chouara Tannery in Fes, Morocco. Image credit: We Animals Media

By 2025 we can expect 430 million cattle to be skinned for leather annually (Siegal, 2016). These cattle are resource-intensive, using vast amounts of land, water, and feed. Producing cattle is inefficient, especially at a time of water shortages and famine around the world. For example, it takes 2,500 gallons of water to produce 1 pound of beef, whereas it takes only 24 gallons of water to produce 1 pound of potatoes (Earth Save, 2020). Comparable amounts of water are needed for tomatoes, apples, carrots, wheat, and other crops as is needed for potatoes. As another example, livestock requires about 4 times more land than crops, meanwhile, the crops supply significantly more calories and protein for people (Brooks, 2018). A great amount of fish is also fed to cattle, meanwhile, fish populations are already quickly diminishing. Raising cattle also requires killing vast amounts of wildlife and clearing trees, all of which would otherwise occupy the land and produce ecosystem benefits.

The outputs of raising cattle are harmful. Manure used as fertilizer creates excessive nitrogen and phosphorus runoff into waterways. This creates algal blooms and depletes the oxygen, creating ocean dead zones. Besides nitrous oxide, fluorinated gases, and carbon dioxide, cows also create harmful amounts of methane. Methane is many times more harmful than carbon dioxide. These greenhouse gases from cattle are a major contributor to climate change.

These are just the environmental concerns associated with cows used for the meat industry. Leather is often considered a byproduct of the meat industry. However, it can more accurately be described as a coproduct, since the hides can be worth more than the other components. Either way, these sustainability concerns exist when it comes to cattle, and creating leather imposes additional concerns.

Before the 1800s, the leather tanning process involved vegetable tannins or oil, or even using the brains of other animals such as pigs. However, to speed up the pace, the world now mostly uses dangerous substances to turn the animal hides into finished leather. About 90% of light leather is chromium tanned (Fei & Liu, 2016), which is what fashion pieces are made from, with the soles of shoes being the exception. While this works fast, it is inefficient and harmful, as “one metric ton of raw material yields only 20% as finished leather product and more than 60% as solid and liquid waste including the highly carcinogenic heavy metal chromium” (Sivaram & Barik, 2019). The dehairing process also uses chemicals such as arsenic sulfide or other harsh chemicals.

Stricter environmental policies in developed countries have led to more outsourcing of leather tanning to developing countries, where there are little if any environmental regulations to protect people and the environment. Developing countries now produce 60% of the world’s leather (Doble & Kumar, 2005) and this allocation is expected to continue to increase. In these developing countries, the chemicals spill heavily into waterways. Toxic runoff can travel into faraway fields, killing crops and contaminating those that survive. Excess leather scraps can be fed to chickens. This all ends up in the food chain and water system consumed by people. The tannery workers - including many young children - often work without personal protective equipment and can be waist-deep in pools of chemically contaminated water. The tannery workers suffer from skin diseases, gastrointestinal and dermatological diseases, and more. In India, scientists found that tannery workers had double the morbidity rate compared to control groups (Gallagher, 2014). In Bangladesh, scientists claim that 90% of their tannery workers will die by age 50 (Mohan, 2008). All of this while working very long hours and for about a dollar or so per day. So that companies can maximize profits.

The health consequences in developed countries do not fare much better. The U.S. Centers for Disease Control and Prevention found that the rate of leukemia among residents near one tannery in Kentucky was five times the US average (Richard E. Sclove et al, 1998). In Italy and Sweden, cancer risks were found to be 20%-50% greater than expected for tannery workers (Rastogi et al., 2007). Indeed, regardless of where we live, people need work - but we all need safe work opportunities. Supporting transitions to safe work will be needed.

Labeling can be ambiguous and misleading. When a leather product is labeled as “made in Italy” or another developed country, this does not show where the leather itself was sourced. Additionally, sometimes leather producers intentionally mislabel dog or cat leather. Even when leather comes from cattle, the cattle live horrifically too. They are often forced to march to their death without water or rest for hours by having chili peppers rubbed into their eyes.

Even with the finished product, there are some concerns. Leather clothing oxidizes hexavalent chromium, which is the same chemical that Erin Brockovitch famously sued a utility company for dumping into waterways. Finally, throwing out leather clothing to biodegrade emits more greenhouse gases (albeit this is a problem for many textiles that are left to decompose).

All of these reasons may be why consumers have been increasingly concerned about using leather over the last 5 years (Arnett, 2019). Luckily, we have the power as consumers to drive change. Leather in particular is booming with innovative alternatives to choose from. Gone are the days when our only alternatives were the cheap polyurethane that crumbles apart shortly after buying a product. There have even been improvements to that, where a microfiber backing is used instead of polyester which makes the material durable and last for many years to come. However, even though polyurethane is the lesser evil and has half the negative environmental impact of cow-derived leather (Pulse of Fashion Industry Report, 2017), we can do better. We are seeing many bio-based vegan leathers, made from things like coffee beans, grapes, mangos, mushrooms, pineapple leaves, apples, and cactus.

If you’re really set on having traditional leather, there is innovation coming this way as well. Although some are hopeful in reducing methane from cattle by feeding them lemongrass, we need far better results. Unfortunately, band-aid solutions will only offer miniscule results without solving the cause of the problem. Any progress would easily be countered by the rising consumption levels due to the exponentially growing human population and rising economies in highly-populated China and India. Feeding cattle lemongrass has been said to reduce the methane emissions of cattle when they are alive by one-third (Valinsky, 2020). However, meat consumption is expected to double by 2050 (Food and Agriculture Organization of the United Nations, 2019) and we are already pushing and surpassing the environmental thresholds of the planet (Steffen et al, 2015).

Instead, the kind of numbers and results we need to see can come from biofabrication. Biofabrication is the same as clean meat but for the animal skin specifically, which is easier to create. Producing leather (and meat) this way means we no longer need to produce and slaughter animals. This takes away all of the resource-intensive and animal waste output problems. We can prevent breeding grounds for diseases when we no longer cramp animals together on a mass scale. We can fine-tune to our needs, such as deciding how soft we would want the leather to be. There would be no flaws, such as insect bites on the hides. We could create the skins to specific shapes to further reduce waste. There would be no need for the chemical process to remove hair since there would not be any. Imagine leather-makers working in clean facilities transparent to the public. You can watch a TEDx talk about biofabrication here.

REFERENCES

Arnett, G. (2019, November 11). “Brands are phasing out fur: could leather be next?”. Vogue Business, Retrieved July 28, 2020 from https://www.voguebusiness.com/sustainability/fur-leather-luxury-poll-peta

Brooks, N. (2018). “Chart shows what the world’s land is used for … and it explains exactly why so many people are going hungry”. One Green Planet. Retrieved July 28, 2020 from https://www.onegreenplanet.org/news/chart-shows-worlds-land-used/

Doble, M. and Kumar, A. (2005). Chapter 12: Tannery Effluent. Biotreatment of Industrial Effluents. Pages 133-143. https://doi.org/10.1016/B978-0-7506-7838-4.X5000-3

Earth Save (2020). Food choices and the planet. Retrieved July 28, 2020, from http://www.earthsave.org/environment.htm

Fei, Y. and Liu, C. (2016). Chapter 12: Detoxification and resource recovery of chromium-containing wastes. Environmental Materials and Waste: Resource Recovery and Pollution Prevention. Pages 265-284. https://doi.org/10.1016/C2014-0-05144-1

Food and Agriculture Organization of the United Nations (2019). “Meat and Meat Products”. Agriculture and Consumer Protection Department. Animal Production and Health. Retrieved July 28, 2020 from http://www.fao.org/ag/againfo/themes/en/meat/home.html

Gallagher, S. (2014, February 4). “India: the toxic price of leather”. Pulitzer Center. Retrieved July 29, 2020, from https://pulitzercenter.org/reporting/india-toxic-price-leather-0

Mohan, J. (2008, August 12). ‘The true cost of leather”. UTNE Reader. Retrieved July 29, 2020, from https://www.utne.com/environment/the-true-cost-of-leather

Pulse of the Fashion Industry Report (2017). http://globalfashionagenda.com/wp-content/uploads/2017/05/Pulse-of-the-Fashion-Industry_2017.pdf

Rastogi, S. K., Kesavachandran, C., Mahdi, F., & Pandey, A. (2007). Occupational cancers in leather tanning industries: A short review. Indian journal of occupational and environmental medicine, 11(1), 3–5. https://doi.org/10.4103/0019-5278.32456

Richard E. Sclove et al. (1998). Community-Based Research in the United States (Amherst: The Loka Institute) 52.

Siegal, L. (2016, March 13). “Is it time to give up leather?”. The Guardian. Retrieved July 28, 2020, from https://www.theguardian.com/fashion/2016/mar/13/is-it-time-to-give-up-leather-animal-welfare-ethical-lucy-siegle

Steffen, W. et al. (2015).  “Planetary boundaries: Guiding human development on a changing planet”. Science. 347 (6223). DOI: 10.1126/science.1259855

Valinsky, J. (2020, July 14). “Burger King’s latest sustainability effort: reduce cow farts”. CNN Business. Retrieved July 28, 2020 from https://www.cnn.com/2020/07/14/business/burger-king-cow-diet/index.html