Month: March 2022

Pollution from Mushroom Farming

Published by Joel Ng on March 31, 2022

Hi there! hope you are having a great week.

In today’s blog post, we would be examining the pollution from Mushroom Farming. More specifically, we would be discussing Robinson et al (2019)’s paper on the lifecycle analysis of the Agaricus bisporus, commonly known as the white or brown button mushroom. The white/brown button mushroom is the most common edible mushroom grown in the United States and around 1.4kg are consumed annually per capita (Robinson et al., 2019).

Mushrooms present an interesting Life Cycle Assessment (LCA) case as they are grown under unique conditions, using specially formulated compost in the dark and in climate-controlled environments. This is vastly different from most leafy crops which are traditionally ground in open fields, under direct sunlight and weather conditions.

Figure 1: Agaricus bisporus, White Button Mushroom

In terms of Freshwater usage, around 9kg of freshwater is consumed by each kilogram of mushroom produced (Robinson et al., 2019). The water is mainly used by the background system in the mushroom farms and during electricity generation.

In terms of Global Warming Potential, mushrooms are found to have roughly 2.13 to 2.95 kg CO2 equivalent per kg of mushroom (Robinson et al., 2019). This is mainly contributed by the use of electricity, compost (medium to grow the mushroom) and fuel for transportation (Robinson et al., 2019). Mushrooms also produce a significant amount of Methane due to anaerobic decomposition and compost emissions.

Interestingly, Mushroom is actually comparatively more pollutive than leafy vegetables. According to another lifecycle assessment study, leaf lettuce grown in the United States was found to have a global warming potential of only 0.5kg CO2 equivalent per kg of Vegetables (Stone et al., 2021). Hence, consuming Mushrooms while being better than most meats is still not as good for the environment as vegetables.

Stay tuned for more interesting stories and discussions around food pollution.

References

Robinson, B., Winans, K., Kendall, A., Dlott, J. & Dlott, F. (2019). A life cycle assessment of Agaricus bisporus mushroom production in the USA. Int J Life Cycle Assess 24, 456–467. https://doi.org/10.1007/s11367-018-1456-6

Stone, T. F., Thompson, J. R., Rosentrater, K. A., Nair, A. (2021). A Lifecycle Assessment Approach for Vegetables in Large-, Mid-, and Small-Scale Food Systems in the Midwest US. Sustainability , 13, 11368. https://doi.org/10.3390/ su132011368

Featured image from https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.japantimes.co.jp%2Flife%2F2020%2F11%2F14%2Ffood%2Fyamagata-mushrooms-foraging%2F&psig=AOvVaw0my_OkA5-k4ZSW_Fcy2wDJ&ust=1648805184768000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCID-u4-E8PYCFQAAAAAdAAAAABBH

Hydroponics : Farming without soil

Hydroponics : Farming without soil

Published by Joel Ng on March 27, 2022

In previous articles, we explored how conventional agriculture produces a large amount of soil and air pollution. Globally, 70% of water usage and 38% of non-frozen land is used for growing food, this percentage is expected to rapidly increase as the global population increases (Boylan, 2020). As more land is deforested for agriculture, there would be increases in carbon emissions and a decrease in natural carbon sequestration.

Today, we will explore Hydroponics, a more modern form of agriculture that is believed to be less pollutive and requires significantly lesser land.

Instead of using soil, Hydroponics cultivate plants indoors, with the plant’s bare roots in a continuous shallow stream of nutrient-enriched water (Okafor, 2021). Instead of sunlight, plants receive energy from LED lighting that is tailored to the energy needs of the plants (Boylan, 2020).

Figure 1: Hydroponics plants being grown on vertical racks (Source: Okafor, 2021)

Hydroponics has various advantages over conventional farming. By growing crops in such a controlled environment, Hydroponic crops can be grown vertically, reducing the landuse by up to 90-99% (Boyland, 2020). The reduction in land use results in lesser deforestation, reducing the emission of greenhouse gases and other air pollutants. Furthermore, as the plants are fed fertilizers through water pipes that constantly recycle the nutrient-rich water, there is no surface runoff, preventing water pollution and algae bloom in rivers and lakes (Haspel, 2016).

However, Hydroponics is extremely expensive and energy-intensive. Hydroponics farm requires large amounts of technology and electricity to power lighting, humidity control, ventilation and constantly pump water through the roots of the plants. The production of hydroponic lettuce is estimated to have a carbon footprint that is 7-20 times greater than outdoor lettuce production (Haspel, 2016).

Therefore, while Hydroponics produces lesser soil and water pollution, this technique still has a large environmental impact due to its high electricity usage. Hence, sustainable Hydroponics will need to be paired with renewable, clean energy sources such as solar and hydroelectricity.

What do you think about hydroponics? Did you know that Singapore has a few hydroponic farms?

References

Boylan, C. (2020). THE FUTURE OF FARMING: HYDROPONICS. Retrieved on March 20, 2022 from https://psci.princeton.edu/tips/2020/11/9/the-future-of-farming-hydroponics

Haspel, T. (2016). Will indoor, vertical farming help us feed the planet — or hurt it? Retrieved on March 20, 2022 from https://www.washingtonpost.com/lifestyle/food/will-indoor-vertical-farming-help-us-feed-the-planet–or-hurt-it/2016/06/16/f1faaa98-3332-11e6-8ff7-7b6c1998b7a0_story.html?linkId=26196069

Okafor, J. (2021). Environmental Benefits of Hydroponics. Retrieved on March 20, 2022 from https://www.trvst.world/sustainable-living/environmental-benefits-of-hydroponics/

Featured Image from https://www.gardeningknowhow.com/special/containers/hydroponic-gardening-indoors.htm

Pollutions from Food Transportation

Pollutions from Food Transportation

Published by Joel Ng on March 23, 2022

In this blog, we have mainly discussed the pollution caused by the production of food. However, the transportation of foodstuff via trucks, sea freights or even aeroplanes is another source of pollution. In recent years, some environmental advocates have supported the idea of reducing “food miles”, how far food travels from production to the final consumer, as a means for consumers to reduce their individual pollution footprint (Weber & Matthews, 2008).

In South Korea, the country imports 42.9% of its food and has an extremely high food mileage per capita of 6,000km (Lee, Lee & Lee, 2015). This has resulted in a local movement towards urban agriculture as a solution to reduce the food mileage issue and its associated pollution. According to a study by Lee, Lee & Lee (2015), converting empty urban spaces and rooftops in Seoul into Urban farms can drastically reduce their food mileage and reduce 11,668 tons/year of CO2 emissions. This quantity is equal to the CO2 emissions for 1155 persons on the annual basis of 10.1 tons of CO2emissions per capita in 2007 (Lee, Lee & Lee, 2015).

Does this mean we should all buy local vegetables and meat? Should Singapore implement more aggressive urban/local farming policies?

A separate study based in the United States provides an alternative perspective. Based on Weber & Matthews (2008)’s study they estimate the average American household’s pollution impact related to food to be around 8.1 t CO2e/yr, while delivery “food-miles” only accounts for around 0.4 te CO2e/yr and total freight accounting for 0.9 t CO2e/yr. Therefore, for the average American household, “buying local” could achieve only a 4−5% reduction in GHG emissions due to the majority of the pollution being emitted in the production stage of food (Weber & Matthews, 2008).

Hence, going local or reducing the mileage of food appears to have a limited impact on the overall pollution emitted from food. However, further research specific to Singapore will be needed before making any conclusion. This is because food mileage for Singapore might be very different from the United States, we have limited land for local farming and have a higher dependency on sea freight transportation for food.

References

Weber, C. L., & Matthews, H. S. (2008). Food-miles and the relative climate impacts of food choices in the united states. Environmental Science & Technology, 42(10), 3508-3513. https://doi.org/10.1021/es702969f

Lee, G., Lee, H., & Lee, J. (2015). Greenhouse gas emission reduction effect in the transportation sector by urban agriculture in seoul, korea. Landscape and Urban Planning, 140, 1-7. https://doi.org/10.1016/j.landurbplan.2015.03.012

Featured Image from https://www.dbs.com/livemore/food/how-to-minimise-food-loss-during-storage-and-transportation.html

Singapore’s Agriculture Air Pollution

Singapore’s Agriculture Air Pollution

Published by Joel Ng on March 20, 2022

Wait a moment, Singapore has an agriculture sector? Personally, I wasn’t aware that Singapore has any serious food production until one of my climate change modules (GE4234) discussed this topic. While food production may have been a minor contributor to Singapore’s economy, it has an outsized contribution to Singapore’s air pollution, especially in terms of Greenhouse gases like Carbon dioxide and Methane.

In today’s blog post, I would share some of my analysis of Singapore’s historical emission data provided by The Comprehensive Accounting of Land-Use Emissions (CALUE) database (Hong et al., 2021). The dataset includes the historical emission (from 1961-2017) for each country due to land activities. Do check out the dataset if you are interested to conduct your own analysis.

I have analysed the data and created the visualisations below using Python. The dataset has been filtered to only focus on Singapore’s emissions.

In terms of overall Greenhouse gas emissions, the largest contributor is the Carbon Dioxide (CO2) generated from the conversation of land for Agriculture (LUC-Crops). Another major contributor is the Nitrogen dioxide produced from the use of fertilisers and Pig Manure.

Focusing specifically on CH4, from 1961 – 2017, the net emission of CH₄ due to land use in Singapore is 7,519,195.19 MT CO₂-eq. The largest contributor has been the management of manure from pig farms, which accounts for 83% of all of Singapore’s methane emissions. However, by 1991, the annual emission of CH₄ from all sources was under 2000 MT MT CO₂-eq per year. The decline in emissions was likely due to Singapore’s shift away from agriculture in the 1990s, reducing agriculture and food production to less than 1% of the island’s land (Teng, 2019).

Moving to CO2 emissions, the annual emissions from most land-use activities have been on the decline since the early 1990s and have since reached an extremely low level. The only exception is the CO2 emission from land converted for the growing of vegetables. This suggests that there is still land being converted for farming activities, increasing the annual CO2 emissions. Interestingly, the absorption of CO2 from agriculture abandonment has been declining from 1961 to 1990s and has since stabilised.

In today’s blog post, we have covered how Singapore’s limited food production is also contributing to air pollution and climate change. Hopefully, as Singapore moves towards increasing food production for the 30 by 30 goal, we will do so in a sustainable and minimally pollutive manner.

Hope you have learned something interesting from the analysis of Singapore’s emission data. Do consider checking out the dataset and sharing your own analysis. Stay tuned for more articles on the pollution from food production.

References

Hong, C., Jennifer A. Burney, Julia Pongratz, Julia E.M.S. Nabel, Nathaniel D. Mueller, Robert B. Jackson, and Steven J. Davis. (2021). Global and regional drivers of land-use emissions 1961-2017, Nature, v. 589, p. 554-561, doi:10.1038/s41586-020-03138-y

Teng, P. (2019). Commentary: Is Singapore’s decades-long shift away from agriculture about to take a U-turn?. Retrieved March 10, 2022 from https://www.channelnewsasia.com/commentary/time-for-singapore-s-decades-long-shift-away-from-890676

Featured Image from https://unsplash.com/photos/As_WAg_6BPg

Plastic Farms

Plastic Farms

Published by Joel Ng on March 16, 2022

In a previous article, we examined how the use of pesticides, fertilisers and wastewater irrigation for agriculture results in soil pollution. In today’s article, we will focus on the use of plastic in agriculture and its impacts on our environment.

In 2019, the European Union alone used over 300,000 tonnes of plastic in Crop production (FAO, n.d.). This represents a significant source of soil pollution and secondary pollution when the plastic is eventually disposed of/burned.

One of the most common sources of plastic in Agriculture is Mulching films. In 2011, it was estimated that over 20 million hectares of farmland in China is covered with plastic film (FAO, n.d.). Mulch Films are plastic sheets used to cover the soil to prevent contamination of the crops and to protect the soil from atmospheric agents, drying and temperature fluctuations (Sotrafa, 2021). Using mulch is found to increase crop yields by 30% since it protects seedlings by limiting evaporation, reducing weed and pest pressures (BBC, n.d.).

Figure 1: Mulch Film covering soil (Sotrafa, 2021)

Another major group of plastics used in Agriculture is Greenhouse Film and Protective Netting. In many countries, greenhouses are used to regulate temperature and precipitation to ensure the continuous growth of crops throughout the year. However, in many developing countries, plastic films and nettings are used as insulators instead of glass due to their comparatively lower cost (FAO, n.d.). These plastic films and nettings will degrade after multiple harvests, requiring more plastic for replacement.

Figure 2: Plastic Greenhouse
Source: https://www.thedailygardener.com/best-greenhouse-plastic

In addition, Agriculture produces numerous other plastic waste such as seedling trays, pesticides containers, irrigation tubing and seed packing.

The plastic used in farms are contaminated with soil, pesticides and fertilisers making it extremely costly and inefficient to recycle, leaving only burning and burial as the main form of disposal (BBC, n.d.). Most plastics are also non-biodegradable and will over time break down into smaller particles, microplastics. The microplastics can then be ingested by organisms and be passed up the food chain (FAO, n.d.). Furthermore, plastic pollution negatively affects plant growth by altering the activity of soil microorganisms, soil structure and root development (FAO, n.d.).

Today’s article has covered how maximising agriculture yield can produce large quantities of plastic pollution and waste. Do you think we should sacrifice some crop yield to reduce plastic pollution? Thank you for reading this week’s post. Hope you have a great week ahead.

References

BBC (n.d.). Why food’s plastic problem is bigger than we realise. Retrieved on March 09, 2022 from https://www.bbc.com/future/bespoke/follow-the-food/why-foods-plastic-problem-is-bigger-than-we-realise.html

FAO. (n.d.). Chapter 3: Sources of Soil Pollution. Retrieved on March 09, 2022 from https://www.fao.org/3/cb4894en/online/src/html/chapter-03-3.html

Sotrafa. (2021). What is a mulch film?. Retrieved on March 09, 2022 from https://sotrafa.com/en/what-is-mulching-film/#:~:text=Mulching%20is%20an%20agricultural%20technique,is%20necessary%20for%20vegetative%20development.

Featured Image from https://www.bbc.com/future/bespoke/follow-the-food/why-foods-plastic-problem-is-bigger-than-we-realise.html

Reducing greenhouse gas emissions from rice farming.

Reducing greenhouse gas emissions from rice farming.

Published by Joel Ng on March 12, 2022

Hi there! Hope you are having a great week so far. Today, we would be discussing the emission of greenhouse gases due to rice farming and potential solutions to improve the problem.

Rice is a staple in most Southeast Asian countries. Personally, I won’t be able to go a day without having rice in at least one of my meals. Unfortunately, our beloved rice is actually a major contributor of greenhouse gases, contributing to global climate change.

Rice paddies produce large amounts of Methane (CH4) and Nitrous Dioxide (NO2), both potent and persistent greenhouse gases. Global rice farming is estimated to produce 20-40 Tg/yr of Methane, accounting for 10-20% of the global anthropogenic emissions of methane (CH4) (Li et al., 2018). On the other hand, rice cultivation also emits nitrous oxide (N20), at an estimated rate of 32 Gg N2O-N yr−1 (Li et al., 2018).

Methane is produced by the anaerobic decomposition of organic material in flooded rice fields, the gas then escapes to the atmosphere through the rice plants (IPCC, 1996). Nitrous Dioxide is produced by soil microorganisms and the rice plants act as a channel, emitting them into the atmosphere (Timilsina et al., 2020).

According to Li et al. (2018) study, the use of the Water Saving Irrigation Technique as opposed to conventional irrigation which is characterised by leaving the rice field continuously flooded reduces Methane production. The Water-Saving Irrigation method involves alternating flooding and draining the fields depending on the stage of the rice plant. This method is found to reduce Methane emissions by over 30% while providing a similar rice yield (Li et al., 2018).

The same study also found that the use of Modified Nitrogen fertilisers such as controlled release Urea (CRU), Uresase inhibitor (UI) has the potential to reduce N20 emissions (Li et al., 2018). When compared to conventional fertilisers, the modified nitrogen fertilisers produces 18-34% lesser Nitrogen Dioxide emissions (Li et al., 2018).

Hope you learned something from this week’s blog post. Stay tuned for more articles about food pollution.

References

Li, J., Li, Y., Wan, Y., Wang, B., Waqas, M. A., Cai, W., Guo, C., Zhou, S., Su, R., Qin, X., Gao, Q., & Wilkes, A. (2018). Combination of modified nitrogen fertilizers and water saving irrigation can reduce greenhouse gas emissions and increase rice yield. Geoderma, 315, 1-10. https://doi.org/10.1016/j.geoderma.2017.11.033

IPCC. (1996). Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories. Retrieved on March 6, 2022 from https://www.ipcc-nggip.iges.or.jp/public/gl/guidelin/ch4ref5.pdf

Timilsina, A., Bizimana, F., Pandey, B., Yadav, R. K. P., Dong, W., & Hu, C. (2020). Nitrous oxide emissions from paddies: Understanding the role of rice plants. Plants (Basel), 9(2), 180. https://doi.org/10.3390/plants9020180

Featured image from https://unsplash.com/photos/jaPjICK8ee8

Are plant based milk actually greener than dairy?

Are plant based milk actually greener than dairy?

Published by Joel Ng on March 8, 2022

Hi there! Hope you are having a great week. Welcome back to Pollutive Food where we discuss the pollution arising from food production. In one of the previous posts, we discussed the water and air pollution from producing Dairy. In recent years, there has been gaining traction for plant-based milk as a supposedly less pollutive and environmentally friendly alternative to Milk from Cows.

In the United States, the dairy alternative has been growing rapidly at 13.2% from 2015 to 2018 while consumption of dairy milk has been on a steady decline for the past few decades (Grant & Hicks, 2018). This has been partly due to the increasing awareness of the environmental impacts of dairy and the rising prevalence of lactose intolerance (Grant & Hicks, 2018). However, is plant-based milk really less pollutive than dairy?

Today, we will examine Grant & Hicks (2018) Life Cycle Analysis of Dairy, Soy and Almond Milk. The study examined the environmental impact at every stage, from production, transportation and in retail stores. Note that the study compares the 3 types of “Milk” in multiple environmental factors but this Blog posts only discuss the Air and Water Pollution portions.

Referring to Figure 1, it is interesting to see that the greenhouse gas pollution (represented by Global Warming Potential) is lowest for dairy and quite similar for all 3 sources of milk. While Soy and Almond produce lesser Greenhouse gas in the production process, the 2 milk type requires more extensive refrigeration and are average transported over a longer distance (Grant & Hicks, 2018). Furthermore, for Almond Milk, the energy use for regular mechanical irrigation (almond requires significantly more water than the other 2 types of milk) and use of nitrogen fertilisers contributed to its greenhouse gas pollution footprint (Grant & Hicks, 2018).

Figure 1: Global Warming Potential per litre of Dairy, Almond and Soy Milk
Source: Grant & Hicks (2018)

In terms of Eutrophication impact (water pollution), Almond and Soy Milk are significantly better than Dairy Milk (See Figure 2). The production of feed for dairy cows is extremely fertiliser intensive and contributes to the eutrophication impacts of dairy milk (Grant & Hicks, 2018). Soy milk has a significantly smaller eutrophication impact as soybean plants can fix their own nitrogen and require fewer nitrogen fertilizers than corn (used as animal feed), almonds and most other crops (Grant & Hicks, 2018).

Figure 2: Eutrophication effect per litre of Dairy, Almond and Soy Milk
Source: Grant & Hicks (2018)

In Today’s blog post, we can see that Plant-based milk (namely Soy and Almond) may not actually be less pollutive as compared to Dairy Milk. The air pollution caused by Milk is highly dependent on the transportation distance, refrigeration in retail stores and source of electricity. The water pollution created is also largely dependent on the specific farm and agricultural practices, though the intrinsic properties of the Soybean plant seem to be significantly less pollutive. Therefore, it is also important to acknowledge the limitation of such lifecycle analysis. Studies conducted in different countries or using different farms will likely yield different results.

Hope you have enjoyed today’s blog post. Do share with me what is your take on Plant-based Milk.

References

Grant, C. A., & Hicks, A. L. (2018). Comparative life cycle assessment of milk and plant-based alternatives. Environmental Engineering Science, 35(11), 1235-1247. https://doi.org/10.1089/ees.2018.0233

Featured image from https://unsplash.com/photos/f5Qpv6wps1Y

Aquaculture Pollution

Aquaculture Pollution

Published by Joel Ng on March 4, 2022

Previously, we explored the pollution produced by the growing of crops and the rearing of livestock. In today’s blog post, we will discuss Aquaculture, industrial farming of fish and its associated pollution.

In recent years, Aquaculture has been gaining traction as it has great potential to contribute to global food and protein security. One popular fish for aquaculture is Tilapia due to its rapid growth, resistance to diseases, low mortality rate, resistance to low oxygen and flexibility in feed acceptance (Guzmán-Luna, Gerbens-Leenes & Vaca-Jiménez, 2021). This made Tilapia the 2nd most farmed fish globally, with 4 million metric tons produced annually (Guzmán-Luna, Gerbens-Leenes & Vaca-Jiménez, 2021). However, as with other forms of industrial-scale food production, there are associated pollution and environmental damages.

Aquaculture causes freshwater pollution due to aquafeed, fertilisers, hormone usage and fish waste. In the case of Tilapia, at its infant stage, testosterone (hormones) are mixed with the water to induce a gender change from female to the faster-growing male. Furthermore, Tilapias are commonly fed phytoplankton and fertilisers have to be added to the water to stimulate phytoplankton growth (Guzmán-Luna, Gerbens-Leenes & Vaca-Jiménez, 2021).

This results in heavily polluted wastewater that may or may not is treated before being released to other water bodies. The nutrient-rich wastewater can then cause nutrient pollution and eutrophication in water bodies. Furthermore, the fish waste and unconsumed hormones will cause the water to be unsafe for human drinking, recreational usage and for other wildlife.

Hope you learn something new about food pollution. Stay tuned to more articles about everything related to food and pollution.

References

Guzmán-Luna, P., Gerbens-Leenes, P. W., & Vaca-Jiménez, S. D. (2021). The water, energy, and land footprint of tilapia aquaculture in mexico, a comparison of the footprints of fish and meat. Resources, Conservation and Recycling, 165https://doi.org/10.1016/j.resconrec.2020.105224

Featured image from https://unsplash.com/photos/6hBIMiHtQhs

Agriculture and Soil Pollution

Agriculture and Soil Pollution

Published by Joel Ng on March 1, 2022

As I was researching more about how Agriculture practices pollute the Air, Water and Land, I stumbled upon an interesting article by the Food and Agriculture Organisation (FAO). The article is extremely detailed and complex, describing a wide variety of causes and impacts of soil pollution due to agriculture activities. In this blog post, I will summarise some of the key findings and observations but do consider reading the full article at Sources of Soil Pollution.

According to FAO (n.d.), agricultural activities pollute soils through (1) Pesticides,(2) Fertilisers, (3)Wastewater for Irrigation, (4) Plastic Materials and (5) Rural Waste). This post will discuss the first 3 types of pollution.

Pesticides

Pesticides are chemical or biological ingredients used by farmers to repel, destroy pests or regulate plant growth. With the rising global demand for food, more pesticides are being used to support more intense agriculture practices. The global usage of pesticide per unit cropland has increased from 1.9 kg/ha in 1990 to 3.3 kg/ha in 2016.

Based on Image 1 below, the Asia region has used the largest amount of pesticides annually.

Image 1: Annual Pesticide usage by region (Source: FAO, n.d.)

While the use of pesticides may help to improve crop yield, they have adverse side effects. Pesticides have long half-lives and can accumulate in the soils and water bodies (if washed into water), causing acute conditions in other organisms. Furthermore, pesticides can be vapourised and transported and deposited beyond the original farmland. Some pesticides also contain trace elements like arsenic, copper and manganese that can be extremely toxic to humans and other animals.

Fertilisers

In order to meet global demand for food, organic fertilizers (e.g. manure, compost) and mineral fertilizers (e.g. Nitrogen, Phosphate) had been used to provide additional nutrients to support crop growth. From 1961 to 2002, the worldwide use of nitrogen (N) fertilization and phosphorus (P) fertilization expanded 7.4-fold and 2.3-fold respectively.

Similar to pesticides, while fertilisers help to improve soil quality and improve crop growth, they do have significant downsides. For instance, the excessive use of nitrogen fertilisers produces nitrous oxide (a greenhouse gas), contributes to soil acidification and eutrophication in nearby water bodies. Even the use of organic fertilisers like animal manure is found to increase antimicrobial resistance in the soil (farmed animals are feed antimicrobial) and increased trace elements like chromium, lead and other toxic metals (minerals are fed to farm animals).

Wastewater for Irrigation

Wastewater has been widely used in developing countries to irrigate, especially for those farms located in or close to cities. This provides urban or peri-urban farms with low-cost resources for irrigation and the organic materials in wastewater minimise the need for artificial fertilisers. As shown in Figure 2, Mexico uses the largest amount of untreated wastewater for irrigation in the world.

Image 2: Countries that use untreated wastewater for irrigation (Source: FAO, n.d.)

However, the use of non-treated or limited treatment wastewater poses a significant risk. Irrigating with untreated wastewater can contribute to the accumulation of trace elements (e.g. lead), organic contaminants and dangerous pathogens in the edible parts of crops. By consuming these crops, humans can develop severe conditions and diseases.

Conclusion: This blog post has demonstrated that the excessive use of fertilisers, pesticides and wastewater for agriculture can result in immense soil pollution with far-reaching impacts. Do check out the original article by FAO for more details. Hope you have a great week and stay tuned for more articles on pollution from food.

References

FAO. (n.d.). Chapter 3: Sources of Soil Pollution. Retrieved on February 25, 2022 from https://www.fao.org/3/cb4894en/online/src/html/chapter-03-3.html

Feature Image : https://www.deccanherald.com/specials/insight/farmers-consumers-and-ecology-fall-prey-to-pesticides-774954.html