#8: Pesticide Case Study: Brazil

Hello everyone! Previously on this blog, much has been mentioned of why farmers choose to use toxic chemicals as well as why they hang around for so long in our environment. Today, we explore more on how pesticides, in this case DDT, is so detrimental to human health, which ultimately led to their ban in the 1970’s in almost all developed countries.

DDT is good for me.” An advertisement for widespread farm, home ...

A poster encouraging the widespread use of DDT

DDT is considered as an endocrine disruptor. Studies have shown that there was reduced sperm count and reduced breastfeeding period. DDT is also suspected of causing spontaneous abortion and premature delivery. DDT’s breakdown product, DDE has also significant evidence for liver cancer mortality. The major source of DDT intake for the general population is through food. Since DDT has a high lipophilicity, food substances like eggs, meat and milk should be most considered when performing studies on DDT intake and its effects.

Biomagnification of DDT in human milk has been observed in parts of Brazil. In the agricultural area of Sao Paulo State, levels of DDT found in human milk was 0.149 mg/kg, was compared with the WHO guidelines of 0.02 mg/kg for cow’s milk. Also, in the capital of Rio Grande do Sul State, 2.98 mg/kg of DDT in human milk was found. The DDT levels in both these studies were high, despite the fact that DDT was prohibited in agricultural use there since 1986.

There aren’t many studies which focus on the fate of DDT which describe the full extent of its harm. However, what we know is they can stay in the environment or in us for a very long time, resulting in bioaccumulation and biomagnification. There are chronic effects which follow from DDT exposure, including hormonal effects.

References:

D.R Vieria, E., P.M Torres, J. and Malm, O., 2001. DDT Environmental Persistence from Its Use in a Vector Control Program: A Case Study. Environmental Reseach, 86(2), pp.174-182.

Photo Credits:

https://www.researchgate.net/figure/DDT-is-good-for-me-An-advertisement-for-widespread-farm-home-and-food-processing-use_fig1_263740149

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#7: Enteric Fermentation… what is that??

Hi guys! Welcome back to our blog. Today we will be sharing with you about a topic called enteric fermentation. So… what is enteric fermentation? Well, enteric fermentation is a digestive process by animals where carbohydrates are broken down by microorganisms into simple molecules for absorption into the bloodstream. And of course, it is a normal and common process in most mammals. But this process is aggravated with the many animals being reared on the green-lands of our Earth for consumption.

A study showed that in Switzerland in 1998, that an estimated 63% of anthropogenic methane emission came from agriculture. And 2 forms were particularly identified, one of which is enteric fermentation of animals which was the larger source (87% of the 63%) and methane formation from manure storage (13% of 63%).

So how does enteric fermentation result in the production of methane? Simply put, the microorganisms used to break down the food molecules in the digestive tract by decomposition and fermentation produce methane as a by-product. Methane is the second largest greenhouse gas that is helping to aid in the terrible growing global warming. In fact, although methane falls short of its main competitor, carbon dioxide, researchers have shown that methane has a stronger ability to trap heat in out atmosphere of up to 28 to 34 greater than its competitor.

I have attached a reference of a paper of the global anthropogenic methane emissions by the Global Methane Initiative. In the paper, it is found out that enteric fermentation produces a 27% out of the global productions of methane, while manure storage from agriculture produces a 3% out of the global productions. The paper also mentioned that in an increase of 5% of methane production from agriculture is predicted in the next 10 years (by 2030).

In a paper by the World Resources Institute in 2019, it was mentioned that almost 70 billion of animals are raised annually for consumption purposes by humans. The biggest single source of enteric fermentation pointed towards our cow burps and manure. Manure left on the ground emits nitrous oxide which is also a stronger greenhouse gas to carbon dioxide. It also mentioned that agriculture would most likely continue to be the major contributor to global greenhouse gas emissions in both developed and developing countries for the coming years. If no climate change actions are carried out towards this low awareness sector of agriculture, greenhouse gas emissions could increase 58% by 2050.

With all these being said, we can see that our agricultural pollution from the rearing of animals is a major aid in the process of global warming and climate change. This is definitely not something we should just watch and we should definitely find ways to help reduce the impacts from our agricultural industry to our globe.

References:

The Federal Office for the Environment (FOEN), Berne Switzerland, 2006. Report To The BAFU Regarding Methane Emission From Swiss Agriculture According To The Guidelines Of The IPCC. [online] Switerland: Institute of Animal Science Animal Nutrition ETH Zurich Switzerland. Available at: <https://www.bafu.admin.ch/dam/bafu/en/dokumente/klima/klima-climatereporting-referenzen-cp1/soliva_c_r_2006.pdf.download.pdf/soliva_c_r_2006.pdf> [Accessed 12 July 2020].

World Resources Institute, 2020. 5 Questions About Agricultural Emissions, Answered. Available at: <https://www.wri.org/blog/2019/07/5-questions-about-agricultural-emissions-answered#:~:text=The%20biggest%20single%20source%20is,in%20the%20past%2020%20years.> [Accessed 12 July 2020].

Climate & Clean Air Coalition. 2014. Enteric Fermentation. [online] Available at: <https://www.ccacoalition.org/en/activity/enteric-fermentation#:~:text=Enteric%20fermentation%20is%20a%20natural,methane%20as%20a%20by%2Dproduct.> [Accessed 12 July 2020].

2020. Global Methane Emissions And Mitigation Opportunities. [ebook] Global Methane Initiative. Available at: <https://www.globalmethane.org/documents/gmi-mitigation-factsheet.pdf> [Accessed 12 July 2020].

Picture Reference:

W. Lyon, T., 2016. 5 Good Reasons You Should Care About Cow Farts & Cow Burps. [image] Available at: <https://www.globalcitizen.org/en/content/5-reasons-cow-farts-matter-and-could-destroy-the-w/> [Accessed 7 July 2020].

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#6: Antibiotic Resistance is one of the results of Agricultural Pollution… how did Agricultural Pollution link to that?

Hi guys! I found some super interesting links of Agricultural Pollution to how it affects human health!

This was one of the more interesting things I have discovered from researching about this category of pollution. Instead of the normal simplistic direct harms to humans, Agricultural Pollution can result in the Antibiotic Resistance of humans! :O

So for this case, it isn’t the normal form of pollution where contaminants contaminate our environment, but instead we are eating contaminated meat directly!

I drew out a diagram to depict the process:

Food Chain!

As you can see from the above food chain, an unassuming simple process where nobody would ever question links to antibiotic resistance!

Agricultural rearing of animals has been around for ages. Animals have been used for consumption or for other purposes such as wool or leather. However, many farmers inject their animals in their farmland with human antibiotics to fight against potential viruses or illnesses that their herd may get. This is a common practice, the antibiotics would remain within the animals even till death and consumption. Many bacteria then start developing a form of resistance to the antibiotics as they are exposed to them when the animals are not sick, misusing the antibiotics. When us humans (being the end of the food chain) consume the meat of the animal we are in fact consuming the antibiotic resistant bacteria! These bacteria can even teach other bacteria to be resistant to antibiotics. This means that bacteria that could have been treated by antibiotics might have developed resistance because of our misuse of antibiotics and our consumption of polluted meat!

A quote on a paragraph I read (link referenced below), “The researchers suggest that developing nations should take action to restrict the use of human antibiotics in farm animals… Otherwise, the unrestricted use of antibiotics in even greater numbers of animals raised for human consumption could lead to the global spread of infectious bacteria that are increasingly difficult to treat.”.

Isn’t this an alarming quote from researchers!! With COVID-19 spreading violently around our little globe, could our irresponsibility to take future proactive measures result in the cause for our future sufferings?

Here’s a video for a official explanation from the Centers of Disease Control and Prevention (CDC):

References:

Princeton University. “Antibiotic resistance in food animals nearly tripled since 2000.” ScienceDaily. ScienceDaily, 9 October 2019. <www.sciencedaily.com/releases/2019/10/191009132321.htm>.

Lindwall, C., 2019. Industrial Agricultural Pollution 101. [online] NRDC. Available at: <https://www.nrdc.org/stories/industrial-agricultural-pollution-101> [Accessed 7 July 2020].

Centers for Disease Control and Prevention (CDC), 2019. Antibiotic Resistance And Food. [image] Available at: <https://youtu.be/o0goMAutjEM> [Accessed 24 July 2020].

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#5: More facts about Agricultural Pollution

Hi guys, welcome back to our 5th post! Sorry for the slow posting this week, we were catching up on lectures and preparing for tutorials!

Let’s back-track a little bit and as a starter, I would like to introduce more about the term “Agricultural Pollution”. So what actually is Agricultural Pollution? Well, as we know, agriculture is about the growing of crops and animals for human consumption and uses, so Agricultural Pollution can mainly come from 2 categories: (1) Pollution from growing crops (as we know most commonly) and (2) Pollution from rearing animals (animals will release their discharges possibly into the freshwater directly, or onto the soils of our land used for agriculture or even the atmosphere).

Animal Rearing

Spraying of pesticides

 

 

 

 

 

So it doesn’t seem like there is much to talk about right..? Well, that’s what we will be researching more about! Agricultural Pollution is of course less infamous than our brother pollution, Atmospheric Pollution or Aquatic Pollution. But there are some links between them. In fact, Agricultural Pollution could lead to both Atmospheric and Aquatic Pollution (worsening the situation than it already is!). The rearing of animals is one of the key polluters to the atmosphere. Cow burping and farting release harmful greenhouse gases (Enteric Fermentation, I would like to cover this in a future post) into the atmosphere, contributing to the already terrifying global warming status. Run-offs from the land being washed into the nearby rivers and lakes could harm our marine life that we consume (Refer to Post #1). Agricultural Pollution is a vicious cycle and we consumers are not well aware of our contributions to it especially in grocery stores, buying and supporting such produce!

So that’s all I have for today! More updates to come! See you! 🙂

 

References:

LINDWALL, C., 2019. Industrial Agricultural Pollution 101. [online] NRDC. Available at: <https://www.nrdc.org/stories/industrial-agricultural-pollution-101> [Accessed 5 July 2020].

Sexton, C., 2020. Damaging Air Pollution From The Agricultural Industry Has Been Underestimated. [image] Available at: <https://www.earth.com/news/damaging-air-pollution-agriculture/> [Accessed 5 July 2020].

2020. Agricultural Pollution. [image] Available at: <http://www.schoolchalao.com/basic-education/show-results/pollution/agricultural-pollution> [Accessed 5 July 2020].

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#4 Eutrophication Case Study: Vancouver Lake

Harmful cyanobacteria blooms is a relevant and pressing issue worldwide. This is usually attributed to increases of dissolved inorganic nitrogen and phosphorus as well as suitable growth conditions.

Vancouver Lake of Washington, USA is a large (~9.3 km2), shallow (mean depth ~1.2 m) floodplain lake that is well known for swimming, bird watching, boating, and fishing. In the past, Vancouver Lake was clear, moderately deep (6-8m) that was flushed during spring and fall. However, since the early 20th century, many forms of rapid urbanisation like hydroelectric dam construction as well as land reclamation took place which caused the uncontrolled sediment load and nutrient load. In the 1960s, there were already cyanobacteria blooms and poor water quality. By the 1980s, the lake had shallowed to an average of 1m in depth.

Currently, the lake depth remains at an average of 1m. The water quality continues to be poor, with high levels of dissolved nitrogen and phosphorus, turbidity and pH. According to the Public Health officials, the lake continues to struggle with cyanobacteria because it is shallow, nutrient-rich without any outlets or freshwater sources and experiences very few rain events but is constantly being exposed to sunlight and warm temperatures. Such algal blooms forces the closure of the lake and swim beach periodically on and off during summer season, in order to protect the health of its visitors.

Vancouver Lake during Cyanobacteria blooms

One interesting fact is that several weeks before cyanobacteria outbreaks, the dissolved inorganic nitrogen availability decreases, hence favouring the N-fixing cyanobacteria to give them an advantage for rapid growth. This was exactly what Prof Taylor mentioned in his freshwater pollution lecture!

References:

Rollwagen-Bollens, G., Lee, T., Rose, V. and M. Bollens, S., 2018. Beyond Eutrophication: Vancouver Lake, WA, USA as a Model System for Assessing Multiple, Interacting Biotic and Abiotic Drivers of Harmful Cyanobacterial Blooms. Water, 10(6).

Photo credits:

https://katu.com/news/local/health-advisory-issued-for-vancouver-lake-over-cyanotoxins-again

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#3: Why Pollution of Human Synthesised Chemicals are Widespread

Welcome back! Today we explore why pollution caused by human synthesised chemicals used in agriculture are so widespread.

The key property that these chemicals possess is their PERSISTENCE.

They are usually very stable organic compounds, especially since most of them are halogenated. They do not degrade easily, lasting in the environment for very long periods of time, even up to a few decades. This persistence is also determined by the surrounding environment and climate, where the pesticides persist 3-8 times longer in cold climates compared to temperate ones. Such chemicals contaminate the air, soil and groundwater.

Hence, when such pesticides are applied, they tend to have widespread and prolonged effect on all the humans, wildlife and organisms. At the target site, the pesticides may enter the surface waters or volatilise into air after being sprayed. The excess pesticides applied onto the crops may also leak into groundwater sources. From the surface waters, the pesticides may reach the aquatic organisms, including those in the sediments. From the air, the pesticides may also get deposited onto the soil.

Due to their persistence, the pesticides are able to see through many different stages of natural environment processes to contaminate and remain in air, soil and water sources.

This is a compressed summary, to find out more, head to this link https://www.who.int/ceh/capacity/Pesticides.pdf provided by the World Health Organization.

 

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#2: Why Human Synthesised Chemicals are so Attractive

Hi everyone!

Today we bring to you a short introduction about the usage of toxic chemicals in agriculture, highlighting the more prominent ones, which are so persistent in our environment.

The use of pesticides in agriculture is not something new, in fact it has been with us since 2000BC, where elemental sulfur was used. However, only in the past 100 years or so, did humans create the first man-made pesticides. There were so many advantages of using them.

One of the earliest and most heavily used pesticide was Dichloro-diphenyl-trichloride (DDT). It was first synthesised in 1874 by an Austrian chemist named Othmar Zeidler. After many years, in 1939, Swiss chemist Paul Muller found it to be very effective in killing insects. DDT came rapidly to the United States, with rampant usage of this newly found chemical. For discovering DDT’s unique insecticidal properties, Paul Muller received the Nobel Prize in 1948. Since this discovery was well received, approximately 1,350,000,000 pounds of DDT was used 30 years before its ban in the US. DDT wasn’t expensive yet extremely effective, giving lots of yield to farmers of cotton, soybean and peanut as compared to without the pesticide.

Decades later, DDT is still a ‘silent’ killer

Another really toxic man-made chemical used as herbicides was 2,4-Dichlorophenoxyacetic acid (2,4-D). It got widespread recognition in 1944 and from then on its usage quickly accelerated. 2,4-D was termed as the ‘wonder drug’, where it could kill more weeds than any amount that could possibly grow. Furthermore, the actual food crop (corn) was left untouched!

Amazon.com : Southern Ag Amine 24-D Weed Killer, White Bottle ...

Now we all know why such usage of chemicals in agriculture was so widespread and prevalent.

 

Photo credits:

https://www.sustainability-times.com/environmental-protection/decades-later-ddt-pesticide-is-still-a-silent-killer/

https://weedkillerguide.com/for-lawns/

References:

Archive.epa.gov. 1975. DDT Regulatory History: A Brief Survey (To 1975) | About EPA | US EPA. [online] Available at: <https://archive.epa.gov/epa/aboutepa/ddt-regulatory-history-brief-survey-1975.html> [Accessed 24 June 2020].

Ganzel, B., n.d. Herbicides Like 2,4-D Introduced During The 1940S. [online] Livinghistoryfarm.org. Available at: <https://livinghistoryfarm.org/farminginthe40s/pests_03.html> [Accessed 24 June 2020].

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#1: Fertilisers… oh fertilisers…

Hello everyone, welcome to our blog and our very first post! As the title goes, an obvious hint about the topic of this post would be about fertilisers!

Agricultural farming has been around for ages. With the advancement in technology, humans have found new efficient and effective ways to grow plantations to produce goods to feed the entire world. And with the growing demand for food quality and stock, it is inevitable that humans would look forth to find ways to improve the growth of our food. And here’s where our handy dandy fertilisers come in!

 

 

 

 

 

So, what actually does fertilisers contain? Let’s take a common fertiliser, urea, for example. Urea, like many other fertilisers, is a nitrogenous fertiliser that we apply into our agricultural fields and plantations. Simply put, it is really harmful for humans to ingest high amounts of nitrogen compounds (10 – 45 and above mg/l). Researchers have shown that too much nitrogen levels in our drinking waters could potentially be considered to be carcinogenic and a causative factor for “blue” babies. (Who knew not only should we avoid unhealthy burnt food; we need to avoid high nitrogen concentration drinking water!) “Blue” baby is a terrifying defect that happens to pregnant women who ingest high nitrogen concentration water. The result could potentially be their babies forming malfunctioned hearts resulting in low oxygen circulation, turning them blue.

There are of course standard guidelines for drinking water emplaced by WHO to abide by (I will leave the reference link below). With the high amounts of fertilisers that is required in our farming nowadays, it is truly worrisome to think about the possible agricultural run-offs due to rain or watering of plantations that end up into our groundwaters. This is especially so that we have scarce water resources (only 0.62% of water on Earth is available) and groundwater is one of our water sources that require the least amount of cleaning. However, when these nitrogen compounds are too high that it goes beyond WHO standards, removal is required using advanced technology and it is really very expensive even for developed countries to afford!

If you think about it, we produce our food to poison our limited scarce water resources. What an irony that we are harming ourselves for our own demands for food! But with that being said, is it possible we can find a way to grow our food efficiently and effectively without slowly poisoning ourselves? Perhaps we will leave that to another blog post! For now, take care and stay safe folks! 😊

References:

Agrawal, G., Lunkad, S. and Malkhed, T., 1999. Diffuse agricultural nitrate pollution of groundwaters in India. Water Science and Technology, [online] 39(3), pp.67-75. Available at: <https://iwaponline.com/wst/article-pdf/39/3/67/36089/67.pdf> [Accessed 25 June 2020].

  1. Rolling Revision Of WHO Guidelines For Drinking-Water Quality. Geneva: World Health Organization.

Picture referenced from:

  1. [image] Available at: <https://www.swiss-singapore.com/knowledge-hub/changing-dynamics-of-urea-trade-in-the-fertiliser-sector/> [Accessed 25 June 2020].
  2. [image] Available at: <https://www.indiamart.com/proddetail/urea-fertilizer-bags-14322681162.html> [Accessed 25 June 2020].
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