Line 99: | Line 99: | ||
</dd> | </dd> | ||
<dd> | <dd> | ||
− | <a href="https://2021.igem.org/Team:Shanghai_United/ | + | <a href="https://2021.igem.org/Team:Shanghai_United/Proof">Proof of Concept</a> |
</dd> | </dd> | ||
<dd> | <dd> |
Revision as of 13:42, 15 September 2021
![](https://static.igem.org/mediawiki/2021/a/a5/T--Shanghai_United--Description00.png)
Threat
According to the WHO, arsenic levels above 10 parts per billion in water are harmful to humans. Levels in Bangladesh, however, are five times as much. The Bangladesh arsenic contamination is pending a solution. "I have no alternative." Uddin, a villager in Bangladesh, helplessly expresses his views towards drinking arsenic-contaminated well water.
What comes to your mind first when talking about arsenic? Arsenic is a naturally occurring element that is widely distributed in the earth's crust. It is found in water, air, food, and soil. In recent years, reports of arsenic poisoning have been increasing year by year.
Arsenic seeps into groundwater through rocks and soil, resulting in drinking water from surface sources (such as wells) that often contain higher levels of arsenic than water from, for example, lakes or reservoirs. In addition to groundwater, arsenic levels of 1.7 μg/L have been detected in the ocean, far exceeding the international regulation of 0.0175 μg/L (Neff, 2009). Irrigation with arsenic-contaminated water sources makes arsenic hazardous to human health from the food side. In addition, arsenic can also enter the human body from external sources, such as paints, textiles, and metal adhesives, through direct ingestion, gaseous inhalation, or skin absorptio. Or it can be absorbed by humans as a component of tobacco (WHO, 2018). Long-term exposure to high levels of arsenic can be harmful to humans, especially to developing infants and children. Although arsenic is not well understood, once it enters the body, the skin and various systems such as the nervous, respiratory, cardiopulmonary, immune, and endocrine systems are affected. In addition, the liver, kidneys, bladder, and prostate, which are responsible for detoxification, are damaged and cannot function effectively (National Institute of Environment Health Science, 2021).
For example, in a village in Hunan, China, 1200 in total 3000 residents have been tested for arsenic poisoning, which was mainly caused by the mining of realgar ore. According to the local hospital, 400 of 600 miners who have been tested for arsenic poisoning died from cancer. For instance, a family of 7 people all died from cancer, and 5 of the cases were determined that they were caused by arsenic poisoning (Chinese Center for Disease Control and Prevention, 2014).
Not only for humans but excessive levels of arsenic can also affect plants and animals in the natural environment. For example, aquatic plants (e.g. algae), zooplankton, and amphibians, or aquatic animals (e.g. snails, fish, crustacean larvae, marine mammals) are all exposed to inorganic arsenic toxicity (Neff, 2009).
Current Solutions
Current major lab detection methods include high-performance liquid chromatography and hydride generation atomic fluorescence spectrometry (HPLC-HGAFS), Inductively Coupled Plasma Mass Spectrometry (ICPMS), and atomic absorption spectroscopy (AAS). However, these arsenic detection methods have certain drawbacks. For example, they are often expensive and time-consuming. Prices range from $20,000-$200,000(USD) and testing may require a trained technician. According to Duo et al. (2016), “ICPMS and HGAFS both have high sensitivity and accuracy, but at the same time have disadvantages such as complicated instruments, cumbersome operating procedures, requiring professional training, high testing costs, and long pre-processing preparation time” (para. 2). There are also numerous pre-treatment methods, namely pressurized tank digestion, microwave digestion, wet treatment, and dry incineration.
Our Goal
In consideration of the above situations we decide to create a more efficient method to conduct the testing. We aim to create an E. coli biosensor that can detect arsenic in its environment and alarm people by expressing GFP. GFP, a green fluorescent protein, is a type of protein that glows neon green when expressed. This specific trait can be used as a quick qualitative test to determine arsenic levels.
Then “ASeeker” came out.
References
(1) Neff, J.M. (1997). ECOTOXICOLOGY OF ARSENIC IN THE MARINE ENVIRONMENT—Review. Environmental Toxicology and Chemistry, 16(5), p.917.
(2) Chinese Center For Disease Control and Prevention (2014). 中国疾病预防控制中心. [online] www.chinacdc.cn.
(3) Ahmad, S. A., Khan, M. H., & Haque, M. (2018, November 30). Arsenic contamination in groundwater in Bangladesh: Implications and challenges for healthcare policy. Risk management and healthcare policy. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6281155/.
(4) Argos, M. (2012, December 1). Arsenic and human health: epidemiologic progress and public health implications. De Gruyter. https://www.degruyter.com/document/doi/10.1515/reveh-2012-0021/html
(5) Arsenic. (2021, May 3). National Institute of Environmental Health Sciences. https://www.niehs.nih.gov/health/topics/agents/arsenic/index.cfm
(6) Institute, E. (2020, May 6). Clay layers and Distant PUMPING Trigger arsenic contamination in Bangladesh Groundwater. State of the Planet. https://news.climate.columbia.edu/2020/05/07/clay-arsenic-bangladesh-groundwater/.
(7) International Agency for Research on Cancer. (2012). Review of Human Carcinogens: C. Metals, Arsenic, Dusts and Fibres (IARC Monographs on the Evaluation of the Carcinogenic Risks to Humans, 100) (Vol. 100C). World Health Organization. https://publications.iarc.fr/120
(8) Matta, G. (2016, June). 2015 - 2016_Mercury, lead and arsenic impact on environment and human health.pdf. Academia.Edu. https://www.academia.edu/38166988/2015_2016_Mercury_lead_and_arsenic_impact_on_environment_and_human_health_pdf
(9) Saha, J. C., Dikshit, A. K., Bandyopadhyay, M. A., & Saha, K. C. (1999, July 1). A Review of Arsenic Poisoning and its Effects on Human Health. ResearchGate. https://www.researchgate.net/publication/248944528_A_Review_of_Arsenic_Poisoning_and_its_Effects_on_Human_Health
(10) SUI Jiachen, YU Hansong, DAI jiayu, et al. Advances in the application of biosensor technology for the detection of heavy metal arsenic in foods[J]. Food Science, 2016, 37(7): 233-238. DOI:10.7506/spkx1002-6630-201607042. http://www.spkx.net.cn
(11) Shaji, E., Santosh, M., Sarath, K., Prakash, P., Deepchand, V., & Divya, B. (2021). Arsenic contamination of groundwater: A global synopsis with focus on the Indian Peninsula. Geoscience Frontiers, 12(3). https://doi.org/10.1016/j.gsf.2020.08.015
(12) The American Cancer Society medical and editorial content team. (2020, August 5). Arsenic and Cancer Risk. American Cancer Society. https://www.cancer.org/cancer/cancer-causes/arsenic.html
(13) Undark Magazine. (2019, December 20). The Poisoning of Bangladesh: How Arsenic Is Ravaging a Nation. https://undark.org/2017/08/16/bangladesh-arsenic-poisoning-drinking-water/
(14) Yogarajah, N., & Tsai, S. S. H. (2015, May 1). Detection of trace arsenic in drinking water: challenges and opportunities for microfluidics - Environmental Science: Water Research & Technology (RSC Publishing) DOI:10.1039/C5EW00099H. Royal Society of Chemistry. https://pubs.rsc.org/en/content/articlehtml/2015/ew/c5ew00099h
(15) Arsenic W.H.O. World Health Organization. February. 2018. [Accessed August 3, 2018]. Available from: http://www.who.int/news-room/fact-sheets/detail/arsenic.
![](https://static.igem.org/mediawiki/2021/1/1d/T--Shanghai_United--homepage06.jpg)