Human Practices

Phase 1: Establishing Core Values

Why is Heavy Metal a problem to solve?

Our project is inspired by several local news stories related to heavy metal pollution problems, including lead contamination in drinking water [1], arsenic and mercury in traditional Chinese medicine (TCM) [2][3], and lead and cadmium pollution from electronic waste in landfills [4]. As stated by the Centre for Food Safety (Hong Kong), four heavy metals—lead, arsenic, cadmium, and mercury—are particularly concerning in food due to their toxicity [5]. Long-term (chronic) exposure to these metals can lead to accumulation in the body and potential organ damage, especially in vulnerable populations like fetuses and young children.

Why use GMO to monitor heavy metal pollution?

Techniques like Atomic Absorption Spectrometry and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) are often used for accurately detecting heavy metal pollution. However, these methods require expensive equipment and are not accessible to the general public. On the other hand, chemical test kits for heavy metals can be useful, but chemical interferences sometimes give misleading false positives or negatives [6]. Our goal is to close this gap by providing a convenient, cost-effective, and dependable method to guarantee public safety.

Could our project be misused? Is it safe?

Safety is always our top priority. In our project, we have genetically modified E. coli to express various chromoproteins (eforRed, dTomato, amilCP, and tsPurple) in the presence of different heavy metals, specifically Zinc, Lead, Cadmium, and Mercury. The E. coli strains we are using (DH5α and BL21) are considered non-pathogenic, making them unlikely to survive in host tissues or cause disease [7].

To ensure safety during the application of the GM E. coli, we have engineered a device, namely the “Metalytic,” that contains the GM E. coli during use. After the application, the device is sterilized with bleach, preventing any leakage of GMOs into the environment.

Phase 2: Stakeholder Mapping

Members of HongKong-JSS represent five distinct high schools, bringing a variety of backgrounds. We identified key stakeholders (Regulation, Public, Science, and Industry) for our project through a comprehensive brainstorming session with the whole team. Stakeholders are those who may be affected by or have an effect on our project. Each stakeholder was recognized based on existing literature and our collective insights. We then developed a stakeholder map to visualize the positioning of each stakeholder, providing a complete overview of the situation.

1. Science

Stakeholders in the science sector play a vital role in shaping the assessment and planning phases of our projects. We consulted several university professors with expertise in environmental and health risk assessments, metal ecotoxicology, genomics, and bioinformatics. Their valuable insights and suggestions significantly contributed to our understanding and approach. This collaboration not only enhances the project's foundation but also ensures that we address critical factors effectively during implementation.

We had a meeting with Prof. Wong Ming-Hung from the Education University of Hong Kong. His major research areas include environment and human health, and remediation of contaminated sites. At present, he is Editor-in-chief of Environmental Geochemistry and Health (Springer) and Book Series Editor (Urbanization, Industrialization and the Environment) of CRC Press.

Prof. Wong provided us with many suggestions regarding the design of our bacterial culturing and colour detecting device, the “Metalytic”. For instance, he suggested that cost and portability could be the major concerns if we want to promote our product to the public. He agreed with our choice of the 4 targeted metal ions, including lead, cadmium, mercury, and zinc, as they were the most common heavy metals contaminants found in Hong Kong. During the interview, he also emphasized the pervasive impact of heavy metals on both health and the environment, illustrating how exposure can lead to serious health issues such as neurological disorders and respiratory problems. He explained that heavy metals can accumulate in the food chain, affecting wildlife and ultimately humans. This interconnectedness highlights the urgency of detecting heavy metals in our surroundings, as early identification can mitigate health risks and help preserve ecosystems.

Heavy metals targeted to detect

Another faculty member we interviewed was Prof. Wang Wen-Xiong, the chair professor in oceanography and environmental ecotoxicology of the City University of Hong Kong.

During the interview, Prof. Wang reviewed our project and provided us with many suggestions. For example, he was concerned about the possible genetic variation of the GM E. coli, such as the choice of E. coli> strains and possible mutation or loss of plasmid DNA when we pass the bacterial culture. In response, we checked the properties of different E. coli strains and decided to use DH5α in our project. It has high transformation efficiency and is the most frequently used E. coli strain for cloning applications. It also has high plasmid transfer rates so that the plasmid transformed into the bacteria is less likely to lose when we pass the culture, and thus our chromoprotein expression experiment results could be more robust. Yet, we are aware that if we want to have a stronger level of protein expression we should use strains like BL21(DE3), or integrate our DNA construct onto the bacterial genome.

Prof. Tsui Tsz Ki, Martin from the School of Life Sciences, the Chinese University of Hong Kong, is an expert in ecosystem biogeochemistry and environmental pollution.

When meeting with Prof. Tsui, he emphasized that to explain the comparative advantage of our detection method, first we need to prove that our method can distinguish between different levels of heavy metal ions. Therefore, we included testing the chromoprotein expression level under different concentrations of heavy metal ions in our wet lab. Together with AI machine learning, we aimed to train our device to differentiate heavy metal levels based on the colour of chromoprotein expressed.

Regarding the design of our hardware, the “Metalytic”, Prof. Tsui was also concerned that variation in temperature may affect the gene expression of the GM E. coli, hence, the detection results. In response, we performed a test by comparing the chromoprotein expression between bacteria cultured at room temperature and 37°C. The results showed that after 24 hours, only bacteria cultured at 37°C can develop visible colour change. Feeding this back to our hardware design, we added a temperature control unit to help maintain an optimal 37°C for the bacterial cultures.

Prof. Ngo Chi Ki, Jacky, from the School of Life Sciences at the Chinese University of Hong Kong, is professionally skilled in protein chemistry, protein expression, and cell biology. He gave us advice regarding the chromoprotein expression in E. coli. During our discussion with Prof. Ngo, he highlighted the necessity of promoting oxygen penetration in the culture medium, which in turn supports bacterial growth and the gene expression of E. coli. In response to his insights, we tested the chromoprotein expression in GM E. coli culture with or without stirring. In our tests, the colour developed is visibly much stronger in GM E. coli culture with stirring after 24 hours. Therefore, we improved the design of our hardware “Metalytic” by incorporating a magnetic stirrer in it.

Additionally, he also recommended sterilizing the load dock before and after each test to prevent contamination of culture or leakage of GMO to the environment. Consequently, we opted to install a low-power UV sterilization light for this purpose, along with a bleach dispensing system to effectively eliminate GM E. coli after use.

Our science teachers, Mr. Chan and Mr. Wong, provided valuable insights. Mr. Chan's suggestions focused on the potential application of GM E. coli, while Mr. Wong offered perspectives on utilizing our device for the detection of heavy metals.

Mr. Chan provided us with advice regarding the design and function of our device, including the use of AI models and IoT technology. He suggested using AI vision instead of a colorimeter as it is more effective since it has a greater database, giving accurate results within a few seconds. He also suggested using IoT technology to send the analytical results to users via SMS.

Mr. Wong raised concerns about using GM E. coli and recommended selecting robust reporter systems. In response, we reviewed the literature and identified potential heavy metal-inducing promoters: pZntR for zinc (Zn), pMerT for mercury (Hg), pCadA and pYodA for cadmium (Cd), and pPbrR for lead (Pb). For reporter genes, we selected dTomato, eforRed, amilCP, and tsPurple. They are visible to the naked eye, facilitating effective monitoring.

Feedbacks to our project

To the design of the DNA construct and testing of the GM E. coli:

1. We focused on detecting four common heavy metals contaminants in drinking water and food: Pb, Cd, Hg, Zn.
2. The design of our construct involved heavy metal-inducing promoters: pZntR (Zn), pMerT (Hg), pCadA and pYodA (Cd), pPbrR (Pb) and chromoproteins: dTomato (Pb), eforRed (Zn), amilCP (Cd), and tsPurple (Hg).
3. To check if our reporter signal is concentration-dependent, we tested the chromoprotein expression level under different concentrations of heavy metal ions.
4. We tested and confirmed that stirring and temperature control at 37°C is essential for robust and efficient chromoprotein expression in E. coli (DH5α).

To the design of the hardware:

1. We employed AI machine learning to determine the concentration of heavy metals based on the colour intensity of the developed genetically modified E. coli culture. This offers greater precision, as it can enhance performance through the use of large datasets, advanced algorithms, continuous learning, and feedback mechanisms.
2. Additionally, we installed a temperature control unit to maintain an optimal temperature for the bacteria to express chromoproteins.
3. We also added UV light to sterilize the bacterial culture chambers before use, preventing potential contamination, along with a bleach dispensing system to eliminate the E. coli and destroy the recombinant DNA after use. This approach prevents potential leakage of GMOs into the environment.

2. Regulation

The regulatory sector involves individuals and organisations responsible for devising, passing, and enforcing laws and regulations. Their actions can significantly impact our project, either facilitating our objectives or potentially hindering them. Engaging with these stakeholders is crucial, as their decisions can shape the framework within which we operate, ensuring compliance while promoting our goals.

We held several team meetings to study Hong Kong Government’s regulations about bio-safety and heavy metal contamination in the city. According to The Genetically Modified Organisms (Control of Release) Ordinance, Cap. 607 (the Ordinance), GMOs intended for contained use, such as GM micro-organisms cultured in laboratories, are not required to notify or document to the authority.

As for heavy metal contamination, The Centre for Food Safety had clearly stated that heavy metals, especially Lead, Cadmium, Zinc and Mercury, are common food contaminants. Their impacts on human health were well documented, while the safety levels for each metal ion were stated in detail in Food Adulteration (Metallic Contamination) Regulations, Cap. 132 sub. leg. V. The Chinese Medicine Regulatory Office, Department of Health also stated that herbal medicines were often contaminated through fertilisers, soil, and during processing, posing serious health issues.

To gain a comprehensive understanding of the 2015 drinking water lead contamination incident, we engaged with representatives from the Water Supplies Department (WSD), including Senior Chemist Mr. Yu Man Tat and Chemist Mr. Chan Kwok Fai. They provided insights into the incident, explaining that it was attributed to the use of non-compliant soldering materials in the water pipes. Their expertise highlighted the critical importance of adhering to regulatory standards to prevent such occurrences in the future.

They also expressed concern regarding the sensitivity of the GM E. coli strain. The WSD utilises parts per million (ppm) as their standard measurement unit, while parts per billion (ppb) is used specifically for lead. Therefore, it is imperative to align the sensitivity of our GM E. coli with the established measurement standards, raising it to the same level of sensitivity as ppm/ppb.

Currently, the WSD and other Government Laboratory of Hong Kong employ Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to detect heavy metal levels in various samples. However, the cost of this testing method, which ranges from $50,000 to $250,000, renders it prohibitively expensive for routine public use.

We interviewed Dr. Mak Yim Ling, an Environmental Protection Officer from the Environmental Protection Department (EPD), about heavy metal pollution in Hong Kong.

Dr. Mak explained that the EPD monitors water quality monthly from over seventy collection points. While heavy metal pollution was primarily from local industry in the 1990s, it has since decreased. Currently, pollution mainly arises from septic tank leaks, agricultural runoff, and improper sewage connections. The EPD investigates any exceedances in heavy metal concentrations in community water sources.

Dr. Mak noted that if our device can enable low-cost, large-scale screening, it would enhance monitoring efforts. However, she stressed the importance of accuracy in detecting specific heavy metal levels to avoid unnecessary public concern. She recommended validating our data against government laboratory results.

Finally, for suspected heavy metal pollution, the public should contact the Water Supplies Department or the EPD, and any new discharges must comply with the Water Pollution Control Ordinance.

Feedbacks to our project

1. In our wet lab experiments and prototype testing, safety precautions have been implemented to ensure that GM E. coli strains are not released into the environment.
2. We utilised the non-pathogenic E. coli strain DH5α, which is recognized as safe for handling.
3. To improve the efficacy of our detection method, we conducted tests across a wider range of heavy metal ion concentrations. Our experiments focused on lead, which demonstrated an effective detection range of 33 to 3300 ppb. Additionally, we successfully detected cadmium at a concentration of 37 parts per million (ppm).
4. Our objective is to develop a more cost-effective and user-friendly alternative to Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for the public to monitor heavy metal contamination in everyday contexts.

3. Public

We conducted one online survey and two public surveys at different stages of our project to gather public opinion. Feedbacks from online and public surveys indicated significant concern among the general public regarding heavy metal contamination. Relating to our solution, a biosensor using GM E. coli to detect heavy metals. There are apprehensions about its cost and usability. If perceived as too expensive or complex, the device may face limited adoption among potential users, particularly in communities affected by heavy metal pollution.

During the initial planning phase of our project, we conducted an online survey to gauge public concern regarding heavy metal pollution. Data from 359 respondents revealed that a significant majority (91%) consider heavy metal pollution in Hong Kong to be a serious issue. A large portion of respondents demonstrated awareness of its consequences, with 81.4% expressing concern about its presence in their living environment. As a result, nearly all participants (96.8%) believe that addressing this pollution should be a priority requiring immediate attention. These findings reassure us that our project aligns with public concerns and has the potential to raise awareness about this critical issue.

During the development of our project, we conducted a public survey to assess perceptions of actively detecting heavy metals in daily life. Feedback from 188 citizens indicated a strong interest in checking for heavy metal contamination in food and water. Many respondents were open to the idea of using GMOs for heavy metal detection. However, their primary concerns centred around our device‘s ease of use, cost, and accuracy.

In late September, we conducted another round of public surveys, presenting our experimental results and explaining how the heavy metal biosensor would operate. Among the 112 citizens who responded, 75.9% expressed a willingness to use our device after the explanation. The primary factors influencing their willingness included safety, ease of use, convenience, and reliability.

However, some individuals expressed reluctance due to concerns about the inconvenience of sample collection, uncertainty regarding machine operation, perceived risks associated with bacteria, and doubts about the device's reliability. These insights highlight areas for improvement in both our detection method and public outreach, and we will incorporate this feedback into our future plans.

Feedbacks to our project

1. We modified the design of our device to simplify assembly.
2. We integrated IoT technology, enabling the device to automatically send alerts to users if detected results exceed safety standards, making it more convenient and user-friendly.
3. We incorporated more durable electronic components to enhance reusability, thereby reducing long-term costs. The expense of replacing GM E. coli is minimal, allowing us to offer discounted pricing to existing customers who have previously purchased the device.
4. In an effort to improve the accuracy of our device, we opted to utilise AI vision instead of a colorimeter, significantly enhancing both effectiveness and precision.
5. Although the public is generally receptive to our detection method, some remain sceptical due to concerns about the inconvenience of sample collection, uncertainty regarding machine operation, perceived risks associated with bacteria, and doubts about the device's reliability.

4. Industry

Understanding the opinions from the industry is important for our project. Their insights can provide valuable perspectives on the practical implications and acceptance of using a synthetic biology approach to detect heavy metal contamination—GM E. coli that changes colour in the presence of heavy metals.

In our research on the industry, our team conducted informative interviews with two registered traditional Chinese medicine practitioners: Dr. Leung Wai Mui from the Holistic Chinese Medicine Clinic and Dr. Ng Siu Man from the PuraPharm Chinese Medicine Clinic. We aimed to gain a deeper understanding of the concerns prevalent within the industry. This understanding is crucial for developing more effective solutions and ensuring that our detection methods can address the industry's needs.

During the interviews, Dr. Leung and Dr. Ng expressed both concerns and curiosity about the use of genetically modified E. coli for enhancing the efficiency of testing heavy metal concentrations in traditional Chinese medicine (TCM). They recognized the potential for our device to facilitate automated safety detection, which could streamline the testing process and ensure higher standards of quality control in TCM. Yet, they also questioned how this technology would be perceived by the public, particularly regarding safety, for example what should the user do with the bacteria after use. Their feedback highlighted the need for clear communication about the technology’s benefits and safety measures to foster acceptance within the community.

Dr. Ng noted that the TCM available in their clinic comes from trustworthy wholesalers. However, customers might be skeptical about the sources of the herbal medicines and whether they are polluted or contaminated. She also stated that our device would be more user-friendly if detection results could be read directly, eliminating the need for mobile devices.

Apart from public perception, Dr. Leung also expressed concerns about the practicality of our device. She mentioned that it may only work with transparent or light-coloured samples, while herbal medicines are often black or brown, which could impact detection results due to colour overlapping with chromoproteins.

Feedbacks to our project

1. Public engagement is essential for alleviating concerns and fostering trust. In response, we are launching an educational program aimed at promoting biosafety and the incorporation of GMOs into everyday life for local primary students, helping them understand the benefits and safety of GMOs. Additionally, we have conducted several public surveys to gain insights into public concerns.
2. We have integrated an LCD screen to facilitate the direct reading of detection results from the device.
3. Furthermore, to enhance public confidence in TCM, we propose a certification program designed to promote high-quality TCM products. This program will ensure that all certified products pass our heavy metal testing, thereby guaranteeing their safety and efficacy.
4. Some TCM preparations have dark colours, which may interfere with the observation of our chromoprotein reporter's colour changes.

Our reflection on human practice

Human practice plays a crucial role in the development and success of our project. Engaging with the public, stakeholders, and experts can foster essential feedback loops that enhance our research and its practical applications.

For instance, we conducted an online survey and three public surveys throughout our project to gauge community sentiment. This engagement has been invaluable in understanding how the public values our work and perceives its importance. Feedback from participants, in particular, played a crucial role in shaping the design of our prototype, ensuring that it is both user-friendly and relevant to their needs.

Throughout our project, we also received valuable suggestions from environmental scientists, toxicologists, and public health experts. Their expertise has been instrumental in identifying potential limitations of our chromoprotein reporter system and recommending improvements. Regular consultations foster a dynamic exchange of ideas, driving innovation and enhancing the scientific rigour of our work.

In summary, human practice is integral to creating effective feedback loops that elevate our project on heavy metal detection. By fostering collaboration, engaging with communities, and iterating based on feedback, we can enhance the impact and relevance of our work.

Phase 3: Gathering Insights
Phase 4: Integrating Feedback

The concern about the danger of heavy metal led us to launch a project to design a machine that detects heavy metal using GM E. coli. During the process, we received assistance and gained valuable suggestions from different stakeholders. Their critical views and feedback helped us optimise our project plan and solution design, making it more effective, feasible, and likely to succeed.

Below is a map showing how influence from different stakeholders feedback to our project and help us to improve and make it more relevant and connected to the wider world.

Here are the details of each human practice event, highlighting the event itself, our reflections on the project, and the feedbacks. In some instances, we were unable to address certain concerns at this time; these have been categorized as “limitations” and will be included in our future plans.

We wanted to interview Dr. Mak Yim Ling to gain expert insights on current water quality issues and pollution sources, as well as the Environmental Protection Department's efforts in monitoring and addressing these challenges. Dr. Mak explained that the EPD monitors water quality monthly from over seventy collection points. While heavy metal pollution was primarily from local industry in the 1990s, it has since decreased. Currently, pollution mainly arises from septic tank leaks, agricultural runoff, and improper sewage connections. The EPD investigates any exceedances in heavy metal concentrations in community water sources. Dr. Mak noted that if our device can enable low-cost, large-scale screening, it would enhance monitoring efforts. However, she stressed the importance of accuracy in detecting specific heavy metal levels to avoid unnecessary public concern. She recommended validating our data against government laboratory results. Finally, for suspected heavy metal pollution, the public should contact the Water Supplies Department or the EPD, and any new discharges must comply with the Water Pollution Control Ordinance. Reflections: After years of effort, the government has successfully improved Hong Kong's water quality. Our device can further ensure that the water used by citizens and the surrounding water bodies maintain high standards. Widespread and large-scale sampling with our device can essentially establish a reliable database that provides accurate monitoring of Hong Kong's overall water quality. Additionally, we need to categorise the data by different types of heavy metal pollution for effective analysis and response. Feedbacks: In our project, we included the cloning and testing of four heavy metal promoters, each using a different chromoprotein as reporters to allow us to distinguish between them. We need to pay special attention to accuracy and reduce the likelihood of false positives to avoid causing unnecessary panic among the public. This issue can be addressed by the use of A.I. machine learning in our project. Limitations: In our study, we aimed to clone and test four heavy metal reporters. However, after repeat testing, only lead and cadmium reporters demonstrated strong and robust signals. Due to time constraints, we could only show that the lead reporter exhibited a concentration-dependent expression pattern. Further cloning and testing are necessary to establish a comprehensive and reliable heavy metal reporter library for the project. Last but not least, our team has conducted extensive educational activities and discussions about potential models. These initiatives have also allowed us to reflect on our project and assess its connections to the broader world. Please also visit our education and entrepreneurship page for more details.