Overview

At present, most available products for removing formaldehyde from the environment rely on physical and chemical methods, which can result in secondary pollution and are not environmentally friendly. However, formaldehyde pollution is widespread. Therefore, we are exploring the use of synthetic biotechnology to address this issue. To achieve this goal, we have conducted a series of interviews with various stakeholders, including the general public, individuals affected by formaldehyde exposure, experts, researchers, and doctors. This comprehensive approach has provided us with valuable insights into the impact of formaldehyde exposure and effective project implementation. The feedback we've received has played a crucial role in shaping our project and strengthening our commitment to using bioremediation technology to combat formaldehyde pollution.

Preliminary Investigation

Literature Research

To begin our project, we conducted thorough research to fully comprehend the significance of addressing formaldehyde pollution. This involved studying the present condition of formaldehyde pollution, its health hazards, and the existing techniques for eliminating it and their constraints. By gaining a broad perspective on the issue, we hope to demonstrate the practical significance of our project and use this knowledge to solicit recommendations from all stakeholders involved.

You are welcomed to read more about the existing research below.

Field Trial

We tested the level of formaldehyde contamination in several newly renovated rooms using a simple method to roughly detect formaldehyde concentration. We compared the results with rooms that had been in use for many years.

We purchased an indoor formaldehyde self-test kit online. It uses the phenol reagent method, known as the MBTH method. In this method, formaldehyde reacts with phenol reagent (3-methyl-2-benzothiazolyl hydrazone hydrochloride, μgrn) to produce zinc. Zinc is then oxidized to a blue color by iron ions in an acidic solution. The color develops after 30 minutes at room temperature and is quantified using colorimetry.

The results showed that the self-test box solution turned blue-green, indicating that the room was moderately contaminated with formaldehyde.

Figure 1. Indoor formaldehyde self-testing kit purchased online
Figure 2. Test results for newly renovated rooms and randomly selected rooms that have been in use for many years
Figure 3. Comparison of results between a newly renovated room (left) and a room that has been in use for many years (right)

Figure 1-3. Test results of the online-bought indoor formaldehyde self-testing kit

  • Reflection

    • Through hands-on practice, we realize that under the influence of renovation materials and new furniture, the formaldehyde concentration in newly renovated rooms does exceed the national safety standards. Formaldehyde pollution treatment needs to be taken more seriously.

Questionnaires Among College Student

We conducted a survey on the issue of pungent gases in classrooms, targeting students in our vicinity. Using the classroom as an example, where students spend most of their time studying and working, our survey aimed to assess the extent of students' concerns regarding the effects of pungent gases on their health and academic performance.

The survey results revealed that the vast majority of students were indeed concerned about the physical effects of pungent gases on individuals. However, there was a lack of understanding regarding the composition of these pungent gases and the specific harm they could cause to the body.

Figure 4. Overview of survey results
Figure 4. Overview of survey results
  • Reflection

    • Considering students' concerns and their limited understanding of pungent gases, it is essential to focus on raising awareness about the hazards of formaldehyde in educational and promotional programs. This emphasis is critical for increasing awareness and prevention of indoor pollutant gases among college students.

    Initially, this survey was exclusively conducted among college students at the project's outset. Going forward, we plan to broaden the scope of our survey to include a wider range of respondents and topics, encompassing questions related to project content and synthetic biology, in order to gather more comprehensive information.

Interviews with Little Red Book Netizens

Little Red Book is a Chinese social platform where users can share lifestyle advice and insights, among other things. Users can leave comments, ask questions, and share their insights with each other. We looked for several users on Little Red Book who had posted personal experiences of formaldehyde hazards.

1 / 3
Figure 5.1
2 / 3
Figure 5.2
3 / 3
Figure 5.3

Figure 5. Little Red Book Online Interview (translated)

The three interviewees conveyed to us messages with commonalities through their different personal experiences:

  • Newly renovated public spaces are often rushed into operation with minimal measures to remove harmful gases from the renovation.
  • Formaldehyde removal methods that can be applied directly are ineffective, inefficient and time-consuming.
  • People exposed to formaldehyde can develop headaches, sore eyes and sore throats. Some have been diagnosed with respiratory diseases and even cancer.
  • People surviving in newly renovated public places protect themselves by wearing masks or gas masks rather than seeking professional formaldehyde removal. This has the potential to add to the burden of normal life.
  • Reflection

    • There is no real, effective and easy-to-implement way to remove formaldehyde. The release of harmful gases from newly renovated houses profoundly affects people's health and quality of life. Wearing a mask or gas mask and using an air purifier does not prevent exposure to formaldehyde, nor does it achieve metabolic removal of formaldehyde and may cause secondary contamination.

    So far, we were even more determined to achieve the goal of metabolizing formaldehyde by genetically engineered bacteria, thus converting the harmful gas into a harmless substance.

Project Advancement

Expert Interviews

This is the first year for our team to participate in the iGEM competition. At the beginning of the project, we interviewed Prof. Guanglei Liu, who has many years of experience in leading teams at the College of Marine Life Science, Ocean University of China. We hoped to get more ideas from Professor Liu regarding synthetic biology, drawing on his experience. We aimed to refine the iGEM idea and make our subsequent actions conform.
During our meeting with Prof. Liu, he emphasized the importance of considering both the practical significance and feasibility of our project during the design phase. This means that we must carefully evaluate our project's potential impact and usefulness and whether it is realistically achievable given the resources and constraints at our disposal. He mentioned, "A project's success lies in its ability to establish a connection with the real world and narrate captivating stories."
Prof. Liu reminded us that according to the background of the project to take into account that the engineered bacteria are exposed to formaldehyde environment. So, when choosing chassis organisms, we should consider whether these bacteria can maintain normal growth and metabolism in this environment.

  • Reflection

    • After considering Prof. Liu's suggestion, we conducted a literature survey on the tolerance of formaldehyde in chassis organisms. Our findings indicated that E.coli can survive in low concentrations of formaldehyde. Therefore, we selected the E.coli BL21 strain as our chassis organism.

Then, we further consulted our PI, Prof. Chunyang Li, regarding the metabolic pathway of formaldehyde in E.coli. Prof. Li's main research interests are to study the metabolism of important organic compounds in the ocean by marine bacteria using technical methods of molecular biology, biochemistry and structural biology, etc.
During our literature review, we initially identified a formaldehyde metabolism pathway called the reductive glycine pathway. The figure below shows that formate is converted to pyruvate via this pathway to be reused in the tricarboxylic acid cycle. However, Prof. Li questioned this part, "This pathway has complicated steps and involves more enzymes. E.coli, especially in the formaldehyde-stressed environment, being introduced too much enzyme is overloaded on E.coli, which is not favorable to the survival of it."

Figure 6. Reductive glycine pathway
Figure 6. Reductive glycine pathway

Prof. Li also pointed out that wild-type E.coli does not possess formaldehyde dehydrogenase. If the enzyme is introduced, the redox balance has to be taken into account. Whether the newly introduced formaldehyde dehydrogenase will compete for NAD in the cell and thus affect the normal survival of the engineered bacteria is also a question that must be considered and addressed.

  • Reflection

    • Prof. Li Chunyang's questions regarding our project were pivotal for its further improvement. We opted for a simpler pathway for formaldehyde metabolism, directly converting it into formate, which is then metabolized into harmless carbon dioxide and water through the catalysis of formate dehydrogenase. This streamlined pathway involves only two enzymes, reducing the stress on E.coli's survival.

    To address the redox equilibrium issue, we conducted an additional round of literature review. We found a research outcome from the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, which provided innovative insights. They biologically synthesized a novel non-natural cofactor, NCD, and modified formaldehyde dehydrogenase, formate dehydrogenase, and malic enzyme. FalDH and FDH can reduce NCD to NCDH, while ME can oxidize NCDH to NCD, thereby achieving redox balance within the engineered bacteria.

Figure 7. Our project communication with Prof. Li and Prof. Liu
Figure 7. Our project communication with Prof. Li and Prof. Liu

Frontline Researcher Communication

On August 16, 2023, we visited Shandong Dongxiao Biotechnology Co. Ltd. to explore the biomanufacturing industry and engage in discussions with frontline researchers about hardware optimization.

Ruicheng Sun, a researcher at Dongxiao Bio-Tech, guided us through various R&D departments and laboratories, explaining the current R&D focus and development status of Dongxiao Bio-Tech, covering topics from strain preservation and inoculation to equipment and instrument usage.

As our project involves designing a device to intake polluted indoor air, metabolize formaldehyde within the device, and release purified air, we recognized that our experience had primarily been within the laboratory setting, and we had yet to delve into the practical aspects of production assembly and parts selection. We sought valuable insights from researcher Ruicheng Sun, focusing on the following areas:

  • Enhancing device efficiency
  • Preventing engineered bacteria leakage and environmental contamination
  • Avoiding odor emissions from the device
  • Safeguarding against foreign bacterial contamination in the air intake.

Drawing from his extensive experience, Sun suggested that we could adapt the bacterial filters and fermentation tanks used in daily production devices to improve the hardware of our project. This modification would effectively address concerns related to engineered bacteria containment and external bacterial contamination. We have provided specific details of these applications in the Hardware Page

Figure 8. Learning and Interviews at Dong Xiao Bio-Tech

  • Reflection

    • Through field research and learning from frontline researchers, we have gained a deeper understanding of the materials and components used in our hardware. This has motivated us to search for parts that align better with the project's goals, ultimately optimizing our hardware.

Respiratory Physician Interview

On August 17, 2023, we visited Zhucheng People's Hospital in Shandong Province to interview Dongming Yuan, the chief physician of the Department of Respiratory and Critical Care Medicine.

Dr. Yuan explained the harmful effects of formaldehyde on the respiratory tract and circulatory system in a clear and concise manner. He highlighted that formaldehyde can affect individuals of any age and body type, leading to different external symptoms. The severity of organ damage depends on the concentration and duration of exposure to formaldehyde in the environment.

He also emphasized the importance of prioritizing respiratory health, particularly after recovering from COVID-19. He hopes that we can popularize the specific dangers of formaldehyde to the body to more people in our future human practice work, and calls on everyone to pay attention to personal respiratory system health after COVID-19 is cured.

Figure 9. Interview and communication with Dr. Dongming Yuan

  • Reflection

    • Through the interview with Dr. Yuan, we gained a more in-depth and detailed understanding of the harmful effects of formaldehyde, a harmful gas, on the respiratory system. This laid the groundwork for our next step in education and public awareness. We decided that part of our subsequent public education would focus on formaldehyde's damage to human organs.

Questionnaires Among the Public

As our project ultimately serves the general public and consumers, we conducted a questionnaire survey in the Licun Night Market, gathering insights from Qingdao citizens and tourists. The survey focused on various aspects related to formaldehyde, including its hazards, sources of pollution, treatment methods, personal experiences, and public acceptance of our synthetic biotechnology project for addressing formaldehyde pollution. To accommodate the preferences of the respondents, we designed both paper questionnaires and an online survey accessible via QR codes.

During our survey, we encountered a concerned citizen who shared her experience with a high-priced air purifier she had purchased for her home. According to her, the air purifier was from a reputable company and came at a premium price, boasting the capability to remove harmful gases and particulate matter. Interestingly, when the air purifier was activated, formaldehyde and TVOC (total volatile organic compounds) levels initially spiked, followed by a gradual decline. While this visual change might suggest effective "formaldehyde removal," in reality, it fell short.

We took the opportunity to explain the working principle of the air purifier to the concerned citizen. We emphasized that while purifiers are effective at removing particulate matter such as PM2.5 and PM10, their efficiency in removing formaldehyde and other chemical substances is not ideal. This is because the removal of formaldehyde and similar chemicals requires a more complex process, involving not only filtration but also catalytic decomposition. The citizen mentioned that the purifier's filter element needed regular replacement, and different filter elements had varying effects on different substances. However, for formaldehyde and similar chemicals, the filter element's effectiveness was relatively weak.

Figure 10. Communication with the lady concerned about indoor air pollution
Figure 10. Communication with the lady concerned about indoor air pollution

Figure 11. Preparations for the survey

Figure 12. Questionnaire surveys conducted by randomly selected citizens or tourists

The questionnaire looks like this:

Survey results revealed that while over 80% of participants expressed concern about the potential health risks associated with formaldehyde, some of them remained unclear about the specific hazards. Furthermore, despite 41.77% of respondents being aware of the national standard for formaldehyde concentration in living rooms, more than half still required clarification. This indicates a continued lack of awareness regarding formaldehyde and the dissemination of national standards among the general public.

Figure 13. Public perception of health hazards associated with formaldehyde
Figure 13. Public perception of health hazards associated with formaldehyde
Figure 14. Public knowledge of national standards for maximum formaldehyde concentration in indoor air
Figure 14. Public knowledge of national standards for maximum formaldehyde concentration in indoor air

Regarding formaldehyde pollution caused by decoration materials, furniture, and fuel combustion, the vast majority of participants successively agreed that these factors may contribute to indoor formaldehyde pollution, which can be regarded as a basic understanding of familiar sources. However, only 75.8% were aware of information about formaldehyde testing and removal methods, which means that a portion of the population may still need to take steps to deal with potential formaldehyde problems.

Figure 15. Public awareness of factors contributing to formaldehyde pollution
Figure 15. Public awareness of factors contributing to formaldehyde pollution
Figure 16. Public awareness of formaldehyde detection and air purification methods
Figure 16. Public awareness of formaldehyde detection and air purification methods
Figure 17. Public experience of adverse symptoms due to excessive formaldehyde levels
Figure 17. Public experience of adverse symptoms due to excessive formaldehyde levels

In the case of the method of genetically modified E.coli for formaldehyde removal, nearly 30% of people said that they could not accept this method. Of these, most were concerned about the potential environmental and health risks associated with E.coli leakage, as well as raising doubts about the performance and regulatory compliance of the technology. Most would be attracted by the product's ability to prevent E.coli leaks from causing human or environmental impacts and to efficiently and evenly absorb and metabolize formaldehyde in indoor air. Those who do not accept synthetic biotechnology-based engineered bacteria for formaldehyde removal are primarily concerned about the escape of E.coli from the device, which could pose a hazard to humans or the environment.

Figure 18. Public acceptance of using genetically modified E.coli to remove formaldehyde
Figure 18. Public acceptance of using genetically modified E.coli to remove formaldehyde
Figure 19. Perceived advantages of the device
Figure 19. Perceived advantages of the device
Figure 20. Concerns about genetically modified E.coli for indoor formaldehyde removal
Figure 20. Concerns about genetically modified E.coli for indoor formaldehyde removal
  • Reflection

    • Our research indicates that there is still a significant way to go in terms of popularizing the hazards of formaldehyde and promoting effective removal methods.

    Now we have a better understanding of people's needs for the safety and efficiency of formaldehyde removal products. This indicates the direction of our further improvement, which is to remove formaldehyde efficiently without affecting health due to leakage of engineered bacteria. For this reason, we have made many efforts in the suicide switch and hardware design to meet consumer expectations.

Conclusion

Integrated human practice allows us to connect and interact with the real world. We discovered more possibilities for our project from the exploration.

We first strengthen our knowledge reserve through literature research. The necessity of developing a safe and effective biological formaldehyde removal method was realized through questionnaires, field formaldehyde detection and interviews with people who had been exposed to formaldehyde hazards. In communication with experts and researchers, we constantly improve the design details to make the project more feasible for practical use. In the interview with the doctors, we further learned about the damage of formaldehyde to human organs, and the encouragement from the doctors greatly enhanced our determination and confidence to push forward the project.

In general, we have gained valuable insights and opinions from all parties through our integrated human practices. This has greatly enhanced our experimental and hardware designs as well as educational outreach. We understand that formaldehyde pollution still affects many people around the world. We believe in working towards a cleaner environment and taking responsibility for protecting people's health with our own efforts.