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on the Health Hazards of an Unfinished Concrete Ceiling Office Environment and the Efficacy of Air Purification Devices(docs.google.com)

1 point by karyan03 1 week ago | flag | hide | 0 comments

In-Depth Analysis Report on the Health Hazards of an Unfinished Concrete Ceiling Office Environment and the Efficacy of Air Purification Devices

Executive Summary

This report provides a comprehensive analysis of the significant health hazards posed by an office environment with an improperly finished concrete ceiling that continuously generates dust, and evaluates the effectiveness of mitigation strategies. The analysis confirms that this environment presents not merely a sanitation issue but multiple potential risk factors that can lead to serious occupational diseases.

The key hazardous component of concrete dust is Respirable Crystalline Silica (RCS), classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC). Prolonged exposure to RCS can cause incurable lung diseases such as silicosis, lung cancer, and Chronic Obstructive Pulmonary Disease (COPD). Furthermore, the dust may contain heavy metals like hexavalent chromium and lead, as well as other irritants, increasing the risk of allergic dermatitis, eye irritation, kidney disease, and autoimmune disorders.

While air purifiers are partially effective in removing airborne fine dust, they are merely a temporary mitigation measure, not a fundamental solution. Air purifiers cannot prevent the continuous generation of dust and do not address the risk of re-suspension of dust that has already settled on surfaces.

Therefore, this report strongly recommends a multi-stage, integrated solution:

  1. Immediate Actions: Conduct precise indoor air quality measurements and analysis of hazardous substance concentrations by professionals. Formally demand defect remediation from the building owner based on the measurement results and Article 623 of the Civil Act. Concurrently, to protect employees, immediately install air purifiers with H13 grade or higher HEPA filters and sufficient capacity (CADR), and implement wet cleaning using HEPA filter vacuum cleaners.
  2. Fundamental Solution: Implement professional repair work to permanently stabilize the concrete ceiling surface, which is the source of the dust. This includes completely removing surface contaminants and then applying a penetrating surface hardener or a low-volatile organic compound (Low-VOC) sealer to eliminate dust generation at its source.
  3. Post-Remediation Management: After the repair work is completed, re-measure the air quality to verify environmental improvement and consider implementing a long-term employee health management program.

These measures are essential for fulfilling the employer's duty to ensure safety and health as stipulated in South Korea's 「Occupational Safety and Health Act」 and 「Indoor Air Quality Control Act」, as well as the building owner's obligation for facility maintenance.

Chapter 1: Origin and Characteristics of the Hazard: Understanding Concrete Dust

The dust generated from an office ceiling is not simple dirt but a specific hazardous substance created due to physical and chemical defects in the building material. To effectively address this issue, a clear understanding of the root cause of dust generation and the hazardous nature of its components is essential.

1.1. The Origin of Dust Generation: Chemical and Physical Defects in Concrete Finishing

The phenomenon of dust generation from a concrete surface is known as 'dusting,' which occurs as a weak, friable layer called 'laitance' on the surface wears away.1 Laitance is a thin, weak film formed when excess water, along with fine particles of cement and aggregate, rises to the surface during the concrete pouring and curing process due to errors.2 This phenomenon signifies not just a dirty ceiling, but an active material degradation process where the surface itself is continuously breaking down and creating new dust. Therefore, periodic cleaning alone cannot solve the problem; a fundamental surface stabilization treatment is imperative.

The primary construction defects that cause laitance formation include:

  • Excessive Water-to-Cement Ratio (w/c): Adding more water than necessary to the concrete mix leads to a porous and weak structure on the surface as the surplus water evaporates, reducing durability.2
  • Improper Curing: For concrete to develop sufficient strength, it must remain moist for a certain period to complete the cement hydration reaction. Premature drying results in incomplete hydration at the surface, leading to a weak and easily friable surface.5
  • Carbonation: This is a chemical process where carbon dioxide (CO2​) from the atmosphere reacts with calcium hydroxide (Ca(OH)2​) in the concrete to form calcium carbonate (CaCO3​). This reaction lowers the alkalinity of the concrete, weakening the surface and promoting dust generation.5

1.2. Microscopic Threat Analysis: Hazardous Components of Concrete Dust

Concrete dust is a complex mixture of various chemical substances, some of which are highly toxic to the human body.

  • Main Components: Cement dust is primarily composed of calcium oxide (CaO) and silicon dioxide (SiO2​), with additional components such as aluminum oxide (Al2​O3​), iron oxide (Fe2​O3​), and magnesium oxide (MgO).8 Chemical analysis of concrete samples has shown a total
    SiO2​ content of about 53.1%.9
  • Key Hazardous Agent: Respirable Crystalline Silica (RCS): The most dangerous component within concrete dust is crystalline silica, particularly quartz.9 Pure cement contains less than 1% quartz, while general concrete can contain about 2.62%.9 Among these, respirable dust particles with a diameter of 5
    μm or less can penetrate deep into the lungs to the alveoli, causing severe lung diseases.9 The International Agency for Research on Cancer (IARC) classifies crystalline silica as a
    Group 1 carcinogen, a substance with clear evidence of carcinogenicity to humans.9
  • Heavy Metals and Other Contaminants:
    • Hexavalent Chromium (Cr6+): Hexavalent chromium can be present due to industrial waste or raw materials used in cement manufacturing.15 It is a potent allergen and human carcinogen, causing allergic dermatitis upon skin contact and occupational asthma and lung cancer upon inhalation.17
    • Other Heavy Metals: Cement can contain trace amounts of various heavy metals such as lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg). Chronic inhalation exposure can be toxic to the nervous system, kidneys, and hematopoietic system.15
    • Radon: The raw materials of concrete, such as aggregates or some industrial by-products, can emit radon gas, a natural radioactive substance.20 Radon is a major cause of lung cancer, and an unfinished concrete surface can be a direct pathway for increasing indoor radon concentrations.

Table 1: Major Hazardous Components in Concrete Dust and Associated Health Risks

Hazardous ComponentPresence in Concrete & SourceMajor Health Risks
Respirable Crystalline Silica (RCS)Fine particles of quartz (SiO2​) from cement and aggregate (diameter ≤ 5 μm)Silicosis, Lung Cancer (IARC Group 1 Carcinogen), COPD, Kidney Disease, Autoimmune Disorders 9
Hexavalent Chromium (Cr6+)Industrial waste and raw materials used in cement manufacturingAllergic Dermatitis, Occupational Asthma, Lung and Stomach Cancer (Human Carcinogen) 16
Lead (Pb)Cement raw materials and some paint componentsNervous system damage (reduced intelligence), kidney damage, hematopoietic dysfunction (anemia), reproductive toxicity 17
Other Heavy Metals (Cd, As, Hg, etc.)Cement raw and supplementary materialsDamage to various organs (kidneys, liver, etc.) and carcinogenicity 15
Radon (Rn)Radioactive gas emitted from aggregates and some industrial by-products (e.g., phosphogypsum)Lung Cancer (second leading cause after smoking) 20
Highly Alkaline ParticlesFormed when calcium oxide (CaO), the main component of cement, reacts with waterEye irritation and damage, skin irritation and chemical burns, respiratory tract irritation 17

Chapter 2: The Spectrum of Health Hazards from Chronic Dust Inhalation

Long-term exposure to dust from an improperly finished concrete ceiling is more than a mere nuisance; it is a cause of various diseases that can potentially be life-threatening. The office environment is characterized by long-term, continuous exposure to relatively low concentrations, unlike the short-term, high-concentration exposure found on construction sites. This exposure pattern significantly increases the risk of chronic diseases rather than acute symptoms. Considering that the total cumulative exposure is a key determinant of disease development, daily exposure for 8 hours over several years in an office can lead to more dangerous outcomes than intermittent high-concentration exposure. The long latency periods of 10 to 20 years or more for silicosis or lung cancer align with a typical career span, making it crucial to recognize that a seemingly "safe" environment today could be the cause of serious illness in the future.

2.1. Impact on the Lungs: Irreversible Pulmonary Diseases

The respiratory system is the primary and most severely affected target organ by concrete dust.

  • Silicosis: This is a representative occupational lung disease caused by inhaling respirable crystalline silica (RCS) particles, and it is an irreversible disease with no cure.13 RCS particles deposited in the alveoli trigger a continuous inflammatory response from immune cells called macrophages, leading to the formation of fibrosis, or scarring, in the lung tissue.11 As fibrosis progresses, the lungs lose their elasticity and become stiff, significantly reducing their gas exchange capacity and causing progressive difficulty in breathing. Long-term, low-concentration exposure, such as in an office environment, is a typical cause of
    chronic silicosis, which develops after a latency period of more than 10 years.26
  • Lung Cancer: The IARC classifies RCS as a Group 1 carcinogen, with clear evidence of carcinogenicity in humans.9 RCS exposure directly increases the risk of developing lung cancer, and the risk is even higher for patients with silicosis.23 This is believed to be because the chronic inflammation and cellular damage caused by RCS promote the development of cancer cells.24
  • Chronic Obstructive Pulmonary Disease (COPD): While smoking is known as the main cause, RCS exposure is also recognized as an independent risk factor for COPD.13 An epidemiological study of residents near a cement plant showed a significantly higher prevalence of COPD compared to a control group, even among residents with no history of occupational dust exposure. This suggests that environmental exposure alone can cause bronchial inflammation and a decline in lung function.19

2.2. Systemic and Multi-Organ Effects: Threats Beyond the Lungs

The harmful effects of concrete dust are not limited to the lungs. Hazardous substances spread throughout the body via the bloodstream or immune system disturbances can affect various organs.

  • Kidney Disease: RCS exposure is reported to cause nephrotoxicity, increasing the risk of chronic kidney disease and renal failure.21
  • Autoimmune Disorders: RCS can disrupt the body's immune system, causing it to attack its own tissues, leading to autoimmune diseases. Rheumatoid arthritis, systemic sclerosis (scleroderma), and systemic lupus erythematosus are known to be associated with RCS exposure.21
  • Skin and Eye Irritation: Concrete dust is an alkaline substance with a high pH and is physically abrasive, causing direct irritation to the skin and eyes.17 Skin contact can cause dryness, itching, and rashes, and allergens like hexavalent chromium can lead to severe allergic contact dermatitis or skin ulcers.17 If it enters the eyes, it can cause redness and pain due to mechanical irritation, and in severe cases, chemical burns or corneal damage.17

2.3. Compounded Hazards: 'Sick Ceiling Syndrome'

An unfinished concrete ceiling can act as a complex source of hazards, causing or exacerbating other indoor air quality problems beyond just dust generation. This can lead to 'Sick Building Syndrome,' where multiple risk factors interact, rather than a single hazardous substance issue.

  • Moisture Absorption and Mold Growth: Concrete is a porous material that easily absorbs and retains moisture.34 An unfinished ceiling is vulnerable to leaks or high indoor humidity, providing an optimal environment for mold growth. Mold releases spores and toxic metabolites (mycotoxins) into the air, which can cause allergies, asthma, and respiratory infections.34
  • Chemical Emissions (VOCs & Ammonia): Modern concrete may contain various organic admixtures to improve workability. From an unfinished surface, these additives or the concrete itself can release volatile organic compounds (VOCs) and ammonia (NH3​).38 These chemicals can cause typical symptoms of 'Sick Building Syndrome,' such as headaches, dizziness, nausea, and mucous membrane irritation.39

These hazardous factors do not act independently but can have synergistic effects. For example, concrete dust particles can act as carriers, adsorbing mold spores or VOC molecules and transporting them deep into the lungs. Also, chronic lung inflammation caused by RCS can increase sensitivity to other respiratory infections or the toxicity of chemical substances. Therefore, an unfinished concrete ceiling should be considered a complex indoor environmental pollutant, not just a simple dust problem, and a comprehensive countermeasure plan should be established.

Chapter 3: Evaluating Air Purifiers as a Mitigation Tool

The use of air purifiers can be considered as an immediate response to the problem of concrete dust in an office. While air purifiers are effective devices for removing airborne particulate pollutants, a meaningful effect can only be expected if their performance and limitations are accurately understood and they are used strategically.

3.1. HEPA Filter Mechanism and Concrete Dust Removal Efficiency

The core of an air purifier is its filter, and the High-Efficiency Particulate Air (HEPA) filter plays a crucial role in removing fine particles.

  • Performance by HEPA Filter Grade: HEPA filters are graded according to European standards (EN1822), with higher grades indicating higher particle removal efficiency. The removal efficiency for the standard particle size of 0.3 μm is as follows: E11 grade (95%), E12 grade (99.5%), H13 grade (99.95%), H14 grade (99.995%).40
  • Suitability for Concrete Dust Particle Size: The particle size of cement dust ranges from 0.05 μm to 5.0 μm, and the most harmful respirable crystalline silica (RCS) exists mainly in the form of fine particles of 5 μm or less.8 An H13 grade HEPA filter is designed to remove 99.95% of particles down to 0.1
    μm in size 45, making it technically very suitable for capturing harmful airborne concrete fine dust. Therefore, in such a hazardous environment, it is essential to use an air purifier equipped with at least an
    H13 grade HEPA filter.

Table 2: Performance Comparison of HEPA Filter Grades in Air Purifiers

Filter Grade0.3 μm Particle Removal EfficiencyTypical Use EnvironmentSuitability for Office Concrete Dust Environment
E1195%General household environmentUnsuitable: Relatively low removal rate for highly hazardous ultrafine particles, providing insufficient protection
E1299.5%General household environmentNot Recommended: Minor performance difference compared to H13 grade can affect long-term exposure levels
H1399.95%Medical facilities, laboratories, homes with sensitive individualsMinimum Requirement: The minimum grade to effectively control the carcinogen RCS
H1499.995%Semiconductor cleanrooms, operating roomsRecommended: Higher removal efficiency can maximize safety
ULPA (U15 and above)99.9995% or higherUltra-precision industrial facilitiesMay be excessive for an office environment, but provides the highest level of safety

3.2. Strategic Placement and Operation in the Office

The performance of an air purifier depends not only on the filter grade. Strategic operation considering the characteristics of the space and the location of the pollution source is essential to maximize its effectiveness.

  • Importance of CADR (Clean Air Delivery Rate): CADR is a key performance indicator (m3/h) that shows how much clean air an air purifier can supply in one hour.46 A higher CADR value means a larger space can be purified more quickly.
  • Calculating Required Capacity: The appropriate air purifier capacity for an office should be calculated based on the volume of the space and the required air changes per hour (ACH). In a high-pollution environment like one with concrete dust, a minimum of 5 ACH is recommended. It is also generally recommended to choose a product with a purification capacity 1.3 to 1.5 times the actual use area.49
    • Calculation Formula: Required CADR (m3/h) = Office Area (m2) × Ceiling Height (m) × Required ACH (minimum 5)
  • Optimal Placement: Since the dust source is the ceiling, placing the air purifier directly below it could cause the dust to scatter more due to strong airflow. The most effective placement is as follows:
    • Height: Install it on a cabinet or stand at a height of 1 to 1.5 m from the floor to purify the air at the breathing level of the employees.52
    • Location: Place it as centrally as possible in the space to maximize air circulation, and keep it at least 1 m away from walls, furniture, and other obstacles that could obstruct airflow.52
  • Filter Maintenance: In an environment continuously exposed to high concentrations of particulate matter like concrete dust, the filter's lifespan is drastically shortened.
    • Pre-filter: The pre-filter, which catches large particles, should be checked weekly and cleaned with a HEPA vacuum cleaner.
    • HEPA Filter: Regardless of the manufacturer's general replacement cycle (usually 12 months), replacement every 3 to 6 months should be considered.55 If the filter becomes clogged with contaminants, the purification efficiency drops sharply, and in severe cases, there is a risk of re-releasing trapped hazardous substances.

3.3. A Critical Perspective: The Clear Limitations of Air Purifiers

While an air purifier is a useful tool, it is by no means a panacea for the current situation. It is very important to clearly recognize its limitations.

  • Airborne Dust vs. Settled Dust: Air purifiers can only remove airborne dust that is floating in the air. Concrete dust particles are relatively dense and quickly settle on all surfaces such as desks, keyboards, and floors due to gravity. This settled dust can be easily re-suspended into the air by human movement, cleaning, or the operation of the HVAC system, and then re-inhaled. Air purifiers cannot solve this massive 'settled dust reservoir' problem.
  • Continuous Source of Pollution: The most fundamental limitation is that the ceiling is a 'continuous source of pollution' that constantly generates new dust. An air purifier is like pouring water into a bottomless pit; it only removes the pollution as it is generated but cannot stop the pollution from occurring in the first place.

In conclusion, an air purifier is a palliative measure, not a fundamental solution. That is, its significance should be limited to its role as an essential 'first aid' or 'bridge' to reduce the immediate inhalation risk to employees until a permanent solution is implemented. One should not become complacent that the problem is solved just by using an air purifier; it is imperative to move on to measures that eliminate the root cause of the pollution.

Chapter 4: Permanent Solutions: Source Control and Remediation

Beyond temporary risk mitigation through air purifiers, to protect the long-term health of employees, the problem must be permanently solved by repairing the concrete ceiling itself, which is the source of the dust. This requires a systematic approach consisting of two stages: contamination removal and surface stabilization.

4.1. Stage 1 - Contamination Removal: Professional Cleaning Protocol

Before any surface treatment work, it is essential to safely and effectively remove the existing concrete dust that has spread throughout the office space. Improper cleaning methods can actually worsen the situation.

  • The Danger of Dry Cleaning: Using a regular broom or a standard vacuum cleaner is strictly prohibited. These methods are extremely dangerous as they re-suspend fine respirable silica particles into the air, drastically increasing the exposure level of the worker.59
  • Essential Cleaning Methodology: The following professional methodology must be followed for safe contamination removal.
    • HEPA Filter Vacuuming: An industrial vacuum cleaner equipped with a certified HEPA filter that can capture over 99.97% of fine particles without re-releasing them into the air must be used.59 All surfaces, including the ceiling, walls, furniture, and floor, should be vacuumed.
    • Wet Cleaning: After HEPA vacuuming, all surfaces should be wiped down with a damp microfiber cloth or mop. Water helps to prevent dust from becoming airborne and effectively captures it. Cleaning should always proceed from top to bottom (ceiling → walls → furniture → floor) to guide contaminated particles downward.59 This process may need to be repeated several times until the dust is completely removed.64

4.2. Stage 2 - Source Elimination: Concrete Surface Treatment

After the contamination has been removed, the weak laitance layer on the ceiling surface must be strengthened and the dust particles permanently fixed to prevent further dust generation. This can be achieved by applying a penetrating hardener or a film-forming sealer.

  • Option A: Penetrating Hardeners/Densifiers (Silicate Densifiers):
    • Mechanism of Action: A liquid hardener based on sodium, potassium, or lithium silicate is applied to the surface. This solution penetrates deep into the microscopic pores of the concrete and chemically reacts with the calcium hydroxide (Ca(OH)2​) produced during the cement hydration process. This reaction creates additional calcium silicate hydrate (CSH) crystals, the main component that gives concrete its strength.5
    • Advantages: It becomes an integral part of the concrete surface, so there is no risk of peeling, and it is extremely durable. It maintains the breathability of the concrete and, in most cases, does not contain volatile organic compounds (VOCs), making it safe for indoor application.69
    • Disadvantages: It barely changes the appearance of the surface, so it does not provide an aesthetic finish. If the surface condition is very poor, it may not provide sufficient hardening effect.72
  • Option B: Film-Forming Sealers (Epoxy, Polyurethane, Acrylic):
    • Mechanism of Action: A polymer resin such as epoxy, polyurethane, or acrylic is applied to the surface to form a hard, durable, transparent or colored film. This film physically encapsulates the dust source completely, preventing its release to the outside.73
    • Advantages: The dust-blocking effect is very reliable, and it provides a smooth or glossy aesthetic finish. Epoxy and polyurethane, in particular, have excellent abrasion and chemical resistance.74
    • Disadvantages: It can peel if the surface is not properly prepared, and it can block the breathability of the concrete, potentially causing internal moisture problems. Traditional solvent-based products can release high concentrations of VOCs, creating new indoor air quality problems. Therefore, in an occupied office environment, it is essential to choose a 'non-toxic' or 'water-based' product with no or very low VOC content.77

Table 3: Comparative Analysis of Surface Treatments for Indoor Concrete Dust Prevention

CategoryPenetrating Silicate HardenerWater-Based Acrylic SealerWater-Based Epoxy/Polyurethane Sealer
Mechanism of ActionPenetrates concrete pores and chemically reacts to densify and harden the surface itselfForms a thin protective film on the surfaceForms a thick, robust protective film on the surface
Dust Blocking EffectExcellent (strengthens the surface itself)Good (physical encapsulation)Very Excellent (robust physical encapsulation)
Durability/Abrasion ResistanceVery Excellent (no risk of peeling)Moderate (can wear off)Very Excellent (also used for industrial floors)
AestheticsAlmost no change in appearance (matte)Transparent or colored, low-gloss/gloss options availableTransparent or colored, high-gloss finish possible
VOCs ContentAlmost none (Zero-VOC)Low (Low-VOC)Low (Low-VOC)
Considerations for Office Ceiling ApplicationThe safest and most permanent solution. Optimal if aesthetic improvement is not required.Economical and easy to apply, but may have a shorter recoating cycle due to lower durability.Provides the best dust blocking effect and durability. Initial cost may be higher, but it is effective in the long run.

Chapter 5: Regulatory Status and Legal Liability

The issue of concrete dust in an office is not just an environmental problem but is subject to industrial safety, health, and environmental regulations that impose legal responsibilities on both the business owner and the building owner. Understanding the relevant laws and standards is essential for objectively assessing the severity of the problem and establishing the justification for implementing necessary measures.

5.1. The Standard of Risk: Occupational Exposure Limits (OELs)

The objective measure for judging the hazardousness of a work environment is the Occupational Exposure Limits (OELs) set by government agencies.

  • South Korean Standard (Ministry of Employment and Labor): According to the 「Occupational Safety and Health Act」, the exposure limit for respirable crystalline silica (quartz, cristobalite, tridymite) is set at 0.05 mg/m³ as an 8-hour time-weighted average (TWA).12 This standard is intended to minimize the occurrence of pneumoconiosis in almost all workers. For general mineral dust, a standard of 10 mg/m³ applies.80
  • International Standard (U.S. OSHA): The U.S. Occupational Safety and Health Administration (OSHA) operates a more stringent management system. The Permissible Exposure Limit (PEL) is the same as in Korea, 50 µg/m³ (0.05 mg/m³), but a lower level of 25 µg/m³ (0.025 mg/m³) is set as the 'Action Level.' If the airborne concentration exceeds the Action Level, the employer is required to initiate a comprehensive management program, including workplace environmental monitoring, employee training, and medical surveillance.81
  • Implications: In a space like an office where dust generation is not expected, it is normal for crystalline silica not to be detected. If an air quality measurement detects even a trace amount of RCS, it is a sign of a serious problem. If the concentration approaches or exceeds the U.S. OSHA's Action Level of 0.025 mg/m³, it should be considered a clearly hazardous work environment.

5.2. Liability under South Korean Law

This issue imposes legal responsibilities on both the building owner (lessor) and the business owner operating the office (lessee), who are parties to the lease agreement.

  • Building Owner's (Lessor's) Duty to Repair: Article 623 of the South Korean Civil Act states that "the lessor is obligated to deliver the object to the lessee and to maintain it in a state necessary for its use and profit during the term of the contract."85 The continuous falling of hazardous dust from the ceiling constitutes a state in which the lessee cannot safely use and profit from the building for its intended purpose (office space), and thus it is a clear defect. Therefore, the building owner has a legal obligation to repair this defect.
  • Business Owner's (Lessee's) Duty to Ensure Safety and Health: The 「Occupational Safety and Health Act」 imposes a duty on the business owner to maintain and promote the safety and health of workers. This includes all measures to protect workers from hazardous agents (such as dust).87 The business owner must conduct a risk assessment, inform workers about the hazards of the dust and preventive measures 89, and, if necessary, implement health measures such as installing ventilation systems, providing protective equipment, and conducting health examinations.12
  • Multi-Use Facility Owner's Duty to Manage Indoor Air Quality: The 「Indoor Air Quality Control Act」 classifies office buildings of a certain size as 'multi-use facilities' and imposes a duty on the owner, occupant, or manager of such facilities to manage the indoor air quality in accordance with maintenance standards. This includes obligations such as regular pollution level measurements and reporting, and installation of ventilation equipment.90

Thus, the building owner has the primary responsibility to repair the defects of the facility itself, while the business owner has the direct responsibility to ensure the safety of the workers in that space. These two responsibilities are not mutually exclusive and exist simultaneously until the problem is resolved. Therefore, the business owner (lessee) has the legal right to demand immediate repairs from the building owner, and at the same time, has the legal obligation to take their own protective measures, such as installing air purifiers and conducting professional cleaning, until the repairs are completed. It is very important that this entire process, especially the process of notifying the building owner of the problem and demanding repairs, is clearly documented in writing, such as through a certified mail, to secure it as evidence for future legal disputes.94

Chapter 6: Comprehensive Recommendations and Action Plan

Based on the analysis results, a systematic and prioritized action plan to resolve the concrete dust problem in the office is presented as follows. This plan aims to simultaneously pursue immediate risk reduction and fundamental problem-solving, while complying with legal obligations.

6.1. Phased Mitigation Strategy

Phase 1: Immediate Assessment and Documentation (within 1 week)

  1. Professional Intervention: Immediately commission a certified industrial hygienist or an accredited workplace environment measurement institution to conduct a precise air quality measurement in the office. The measurement items must include total suspended dust, respirable dust, and most importantly, the concentration of Respirable Crystalline Silica (RCS).12 This is a key step to prove the severity of the problem with objective data.
  2. Evidence Collection: Document in detail the falling dust from the ceiling, the dust accumulated on surfaces, and the contamination caused by the dust with dated photos and videos. Also, record the health symptoms complained of by employees (cough, eye pain, skin itching, etc.) with the date, time, and a description of the symptoms.94
  3. Official Notification: Send a certified mail to the building owner (lessor) with the collected evidence and a preliminary opinion from the expert. The notice should specify the lessor's duty to repair under Article 623 of the Civil Act, inform them of the health risks to employees due to hazardous substances, and formally request that fundamental repair work be carried out as soon as possible.

Phase 2: Temporary Control Measures (within 1-2 weeks)

  1. Air Purification: Immediately purchase or rent and install air purifiers equipped with H13 grade or higher HEPA filters. Install products with sufficient capacity to purify the entire volume of the office at least 5 times per hour, according to the CADR calculation method in Section 3.2 and the recommended placement principles.
  2. Contamination Spread Prevention: Conduct an initial deep cleaning by a professional cleaning company according to the method described in Section 4.1 (HEPA vacuuming and wet cleaning). Thereafter, until the repair work is completed, intensify the cleaning cycle (e.g., daily) in the same manner to minimize the re-suspension of settled dust.
  3. Employee Communication: Transparently explain to all employees the current situation, the identified health hazards, the temporary measures the company is taking to protect them (operating air purifiers, special cleaning, etc.), and the future plan (fundamental repair). This is very important for alleviating employee anxiety and maintaining trust in the company.

Phase 3: Permanent Remediation (within 2-6 weeks)

  1. Contractor Selection: In cooperation with the building owner, obtain quotes from professional concrete surface treatment contractors. When selecting a contractor, it is essential to confirm their experience with indoor work and their use of low-volatile organic compound (Low-VOC) or non-toxic products.
  2. Construction Implementation: To minimize further exposure to employees, coordinate for the work to be carried out outside of business hours, such as on weekends or at night, if possible. The construction process must include the following:
    • (1) Isolation and Protection of the Work Area: Completely seal off the work area with plastic sheeting, etc., and protect furniture and equipment.
    • (2) Surface Contamination Removal: Once again, carry out professional dust removal work as described in Section 4.1.
    • (3) Surface Treatment: Referring to the contents of Section 4.2 and Table 3, apply the most suitable low-VOC surface treatment (penetrating hardener or film-forming sealer) for the site conditions and budget.
  3. Ventilation and Curing: After construction, provide sufficient ventilation according to the manufacturer's instructions to exhaust residual chemicals, and ensure sufficient curing time for the treatment to fully harden.

Phase 4: Post-Verification (from week 7 onwards)

  1. Air Quality Re-measurement: After the surface treatment has fully cured, conduct an air quality re-measurement through the same institution commissioned in Phase 1. Confirm with data that the concentrations of respirable dust and RCS have decreased to a safe level (not detected or at natural background levels).
  2. Result Sharing: Share the verified results with the building owner and all employees to inform them that the problem has been completely resolved.

6.2. Long-Term Health and Safety Management

  1. Regular Air Quality Checks: Even after the repair work, it is advisable to check the indoor air quality regularly, such as annually, to confirm that the effect of the surface treatment is maintained and to check for other potential sources of pollution.
  2. Medical Surveillance: If the initial air quality measurement results showed a high concentration of RCS, or if long-term employees complain of respiratory symptoms, the business owner should consult with an occupational health specialist to review the need for a medical surveillance program (job rotation, health examinations, etc.). This is related to the fulfillment of the business owner's obligations under the Occupational Safety and Health Act.12
  3. HVAC System Inspection: During the period of dust generation, it is highly likely that a large amount of concrete dust has accumulated inside the office's HVAC system ducts. This can act as a continuous source of indoor pollution even after the repairs, so it is essential to have the inside of the ducts cleaned and the filters replaced by a professional company.

참고 자료

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  7. Laitance is the weak, powdery, chalky layer of cement dust - All Things Flooring, 9월 1, 2025에 액세스, https://allthingsflooring.com/2017/02/laitance-flowcrete-cement/
  8. 시멘트 제조ㆍ취급사업장에서 발생하는 공기 중 분진의 노출평가, 9월 1, 2025에 액세스, https://www.jksoeh.org/main/download.htm?code=J02704013
  9. 콘크리트 취급사업장의 공기 중 석영 분석방법 비교 Analysis of Quartz ..., 9월 1, 2025에 액세스, https://www.jksoeh.org/main/download.htm?code=J02302005
  10. 한국의 시멘트 공장 근로자들의 흉부엑스선 소견에 대한 연구, 9월 1, 2025에 액세스, https://kiha21.or.kr/monthly/2016/8/SOBGBO_2016_s340_33.pdf
  11. 37. 산화규소, 9월 1, 2025에 액세스, https://www.moel.go.kr/common/downloadFile.do?file_seq=21171222111&bbs_seq=112794&bbs_id=29&file_ext=pdf
  12. 결정형 유리규산 노출 근로자의 보건관리지침 2013. 9. 한국산업안전 ..., 9월 1, 2025에 액세스, https://musa-lab.com/superboard/lib/download.php?wm_table=policy&wm_bid=255&wm_num=0
  13. 결정질 실리카 - 3M, 9월 1, 2025에 액세스, https://multimedia.3m.com/mws/media/2240865O/psd-ia-hazard-awareness-bulletin-crystalline-silica-kr.pdf
  14. 지속적인 근로자 건강관리가 필요한 유해인자의 종류 및 관리방안 마련 연구 (건강관리카드 중 - 안전보건공단, 9월 1, 2025에 액세스, https://kosha.or.kr/oshri/publication/researchReportSearch.do?mode=download&articleNo=419780&attachNo=237085
  15. 시멘트에 대한 오해와 진실, 9월 1, 2025에 액세스, http://www.cement.or.kr/plus/%EC%8B%9C%EB%A9%98%ED%8A%B8%EC%97%90%EB%8C%80%ED%95%9C%EC%98%A4%ED%95%B4%EC%99%80%EC%A7%84%EC%8B%A4.pdf
  16. [단독] 시멘트에 아토피·암 유발 중금속 '뒤범벅' - 한겨레, 9월 1, 2025에 액세스, https://www.hani.co.kr/arti/society/environment/155909.html
  17. 건설현장 보건관리 - 대한건설협회 서울특별시회., 9월 1, 2025에 액세스, http://scak.or.kr/file/aff_offi_doc/2015/%EB%B6%99%EC%9E%842_%EC%95%88%EC%A0%84%EA%B3%B5%EB%8B%A8%ED%99%8D%EB%B3%B4%EC%9E%90%EB%A3%8C.pdf
  18. 콘크리트 분진, 중대재해 요인된다...사고위험 이렇게 예방! - 한국재난안전뉴스, 9월 1, 2025에 액세스, https://www.kdsn.co.kr/mobile/article.html?no=27172
  19. [환경보건 이슈기획Ⅰ-③]콘크리트에 갇힌 도시인, 9월 1, 2025에 액세스, https://www.hkbs.co.kr/news/articleView.html?idxno=312271
  20. 콘크리트 제국의 무서운 진실, '콘크리트 암토피아' - 르몽드 디플로마티크, 9월 1, 2025에 액세스, https://www.ilemonde.com/news/articleView.html?idxno=18378
  21. ICSC 0808 - 석영, 9월 1, 2025에 액세스, https://chemicalsafety.ilo.org/dyn/icsc/showcard.display?p_card_id=0808&p_version=1&p_lang=ko
  22. 결정질 실리카 – FAQ - icare, 9월 1, 2025에 액세스, https://www.icare.nsw.gov.au/-/media/icare/unique-media/global-header/news-and-stories/news/were-speaking-your-language-silica-information-for-workers/silica-fact-sheet---korean.pdf
  23. Quarzkies SB 5 - 8 mm F - Quarzwerke GmbH, 9월 1, 2025에 액세스, https://www.quarzwerke.com/kundeninformation/sicherheitsdatenblaetter?fileUid=89036&type=1688485981&cHash=e651e8d7f2f8e6636c0e6a145c0fe6f4
  24. [SS046] 실리카에 대한 직업적 노출 과학적 증거 및 ... - 안전보건공단, 9월 1, 2025에 액세스, https://www.kosha.or.kr/kosha/data/activity_D.do?mode=download&articleNo=257636&attachNo=139590
  25. 실리카 스마트. - Safe Work Australia, 9월 1, 2025에 액세스, https://www.safeworkaustralia.gov.au/clearlungs/korean
  26. Symptoms and Medical Monitoring | Silica - CDC, 9월 1, 2025에 액세스, https://www.cdc.gov/niosh/silica/symptoms/index.html
  27. Silicosis : MedlinePlus Medical Encyclopedia, 9월 1, 2025에 액세스, https://medlineplus.gov/ency/article/000134.htm
  28. Silicosis - NHS, 9월 1, 2025에 액세스, https://www.nhs.uk/conditions/silicosis/
  29. Silica, Crystalline - Health Effects | Occupational Safety and Health Administration, 9월 1, 2025에 액세스, https://www.osha.gov/silica-crystalline/health-effects
  30. 폐 괜찮다는데 수년간 '콜록'…시멘트 분진 영향 밝혔다 - 연합뉴스, 9월 1, 2025에 액세스, https://www.yna.co.kr/view/AKR20200721061700062
  31. 시멘트공장 먼지로 인한 건강피해 총 6억 2300만원 배상 결정 - KDI 경제교육, 9월 1, 2025에 액세스, https://eiec.kdi.re.kr/policy/materialView.do?num=127005
  32. 작업 현장의 분진 유형 - 보쉬전문가용 전동공구, 9월 1, 2025에 액세스, https://www.bosch-pt.co.kr/kr/ko/dust-control/dust-types/
  33. 시멘트 분진과 환경성질환 - KoreaMed Synapse, 9월 1, 2025에 액세스, https://synapse.koreamed.org/upload/synapsedata/pdfdata/0119jkma/jkma-55-230.pdf
  34. Can Mold Grow on Concrete? 5 Ways To Prevent It - Rainbow Restoration, 9월 1, 2025에 액세스, https://rainbowrestores.com/blog/can-mold-grow-on-concrete
  35. Concrete vs. Other Materials: Which Is More Prone to Mold Growth?, 9월 1, 2025에 액세스, https://themoldassassins.com/blog/concrete-vs-other-materials/
  36. How Concrete Masonry Walls Prevent Mold and Moisture | NMP, 9월 1, 2025에 액세스, https://www.nitterhousemasonry.com/blog/how-concrete-masonry-walls-prevent-mold-and-moisture/
  37. Can Mold Grow on Concrete? Understanding the Risks and Prevention, 9월 1, 2025에 액세스, https://moldinspect.org/can-mold-grow-on-concrete-understanding-the-risks-and-prevention/
  38. Emissions from concrete an indoor air quality issue? - kumlin.biz, 9월 1, 2025에 액세스, http://media1.kumlin.biz/2016/02/Emissions-from-concrete.pdf
  39. Understanding Off-Gassing in Home Construction - Constructor, 9월 1, 2025에 액세스, https://www.constructor.net.au/understanding-off-gassing-in-residential-construction/
  40. HEPA필터 등급과 MERV 등급 확인 - 기계설비 - 티스토리, 9월 1, 2025에 액세스, https://himec.tistory.com/?page=2
  41. 공기청정기 필터, 종류별 어떤 효과가 있을까? (헤파필터, 교체주기, 청소 총정리) - 아정당, 9월 1, 2025에 액세스, https://www.ajd.co.kr/contents/basic-tip/detail/%EA%B3%B5%EA%B8%B0%EC%B2%AD%EC%A0%95%EA%B8%B0%20%ED%95%84%ED%84%B0%2C%20%EC%A2%85%EB%A5%98%EB%B3%84%20%EC%96%B4%EB%96%A4%20%ED%9A%A8%EA%B3%BC%EA%B0%80%20%EC%9E%88%EC%9D%84%EA%B9%8C%3F%20(%ED%97%A4%ED%8C%8C%ED%95%84%ED%84%B0%2C%20%EA%B5%90%EC%B2%B4%EC%A3%BC%EA%B8%B0%2C%20%EC%B2%AD%EC%86%8C%20%EC%B4%9D%EC%A0%95%EB%A6%AC)-6393
  42. HEPA필터 등급 바로알기! - 에누리 쇼핑지식 구매가이드, 9월 1, 2025에 액세스, https://www.enuri.com/knowcom/detail.jsp?kbno=579941
  43. 공기청정기 필터 높은 등급이 필요없는 이유! - 노써치, 9월 1, 2025에 액세스, https://nosearch.com/contents/encyclopedia/season/air_purifier/40
  44. 공기청정기 헤파필터, 등급보다 중요한 3가지! 꿀팁 정리 - 아정당, 9월 1, 2025에 액세스, https://www.ajd.co.kr/contents/basic-tip/detail/%EA%B3%B5%EA%B8%B0%EC%B2%AD%EC%A0%95%EA%B8%B0_%ED%97%A4%ED%8C%8C%ED%95%84%ED%84%B0%2C_%EB%93%B1%EA%B8%89%EB%B3%B4%EB%8B%A4_%EC%A4%91%EC%9A%94%ED%95%9C_3%EA%B0%80%EC%A7%80!_%EA%BF%80%ED%8C%81_%EC%A0%95%EB%A6%AC-52017
  45. 공기청정기 필터 | 다이슨 | www.dyson.co.kr, 9월 1, 2025에 액세스, https://www.dyson.co.kr/support/purifier-filter
  46. 뉴스 - 공기청정기 CCM CADR이란?, 9월 1, 2025에 액세스, https://www.airdow.com/ko/news/what-is-air-purifier-ccm-cadr/
  47. CADR이란 무엇입니까? Mi 공기 청정기의 CADR? - Xiaomi 코리아, 9월 1, 2025에 액세스, https://www.mi.com/kr/support/article/KA-28303/
  48. 공기청정기 주택 실환경 미세먼지 제거 성능시험 방법, 9월 1, 2025에 액세스, https://www.kaca.or.kr/web_basic/program/mit/download.php?pagen=474&ftype=15&fname=SPS-C_KACA_0036-XXXX_%EA%B3%B5%EA%B8%B0%EC%B2%AD%EC%A0%95%EA%B8%B0_%EC%A3%BC%ED%83%9D_%EC%8B%A4%ED%99%98%EA%B2%BD_%EB%AF%B8%EC%84%B8%EB%A8%BC%EC%A7%80_%EC%A0%9C%EA%B1%B0_%EC%84%B1%EB%8A%A5%EC%8B%9C%ED%97%98%EB%B0%A9%EB%B2%95_%EC%B5%9C%EC%A2%85%EC%88%98%EC%A0%95.pdf&fchecksum=3c4287c37e0b482bba56c7ceb07be38e6de2a4a54e71e575a8ff63c3b886b1e0
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  50. [슬기로운 공청생활 ④] 우리집에 '딱' 맞는 공기청정기 구매 체크리스트, 9월 1, 2025에 액세스, https://news.samsung.com/kr/%EC%8A%AC%EA%B8%B0%EB%A1%9C%EC%9A%B4-%EA%B3%B5%EC%B2%AD%EC%83%9D%ED%99%9C-%E2%91%A3-%EC%9A%B0%EB%A6%AC%EC%A7%91%EC%97%90-%EB%94%B1-%EB%A7%9E%EB%8A%94-%EA%B3%B5%EA%B8%B0%EC%B2%AD%EC%A0%95
  51. 평수별 공기청정기, 잘 고르는 방법 (적정 용량, 효과, 갯수 고르기) - 아정당, 9월 1, 2025에 액세스, https://www.ajd.co.kr/contents/basic-tip/detail/%EA%B3%B5%EA%B8%B0%EC%B2%AD%EC%A0%95%EA%B8%B0%20%ED%9A%A8%EA%B3%BC%2092%25%EC%9D%B4%EC%83%81%20%EB%86%92%EC%9D%B4%EB%8A%94%20%EB%B0%A9%EB%B2%95%EC%9D%80%3F%20(%EA%B3%B5%EA%B0%84%EB%B3%84%20%ED%8F%89%EC%88%98%2C%20%EA%B0%AF%EC%88%98%20%EA%B3%A0%EB%A5%B4%EA%B8%B0)-10811
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  53. What is the Best Location for an Air Purifier? - Rabbit Air, 9월 1, 2025에 액세스, https://www.rabbitair.com/pages/what-is-the-best-location-for-an-air-purifier
  54. Best Placement for an Air Purifier: Top Tips 2025 - Abaco Air Experts, 9월 1, 2025에 액세스, https://abacoairexperts.com/2025/02/06/best-placement-for-an-air-purifier/
  55. HEPA filter replacement guidelines: recommended frequency - Kleanlabs, 9월 1, 2025에 액세스, https://kleanlabs.com/blog/hepa-filter-replacement-guidelines-recommended-frequency/
  56. How Long Do HEPA Filters Last? | Lifespan and Replacement Tips, 9월 1, 2025에 액세스, https://customfiltersdirect.com/blogs/air-filter-blog/how-long-do-hepa-filters-last
  57. How often to change hepa filter in air purifier: 3 proven tips - SonoHealth, 9월 1, 2025에 액세스, https://sonohealth.com/how-often-to-change-hepa-filter-in-air-purifier/
  58. An Air Purifier for Construction Dust: Say Goodbye to Dust and Debris - HEPACART, 9월 1, 2025에 액세스, https://www.hepacart.com/blog/an-air-purifier-for-construction-dust-say-goodbye-to-dust-and-debris
  59. How to Clean Up Construction Dust After Renovation: A Step-by-Step Guide, 9월 1, 2025에 액세스, https://www.blockrenovation.com/guides/maintenance/how-to-clean-up-dust-after-construction
  60. 콘크리트 먼지 청소 꿀팁... : r/HomeImprovement - Reddit, 9월 1, 2025에 액세스, https://www.reddit.com/r/HomeImprovement/comments/oafdvb/best_way_to_clean_up_concrete_dust/?tl=ko
  61. Silica Dust: How to Reduce/Remediate the Health Risk it Presents on Construction Sites, 9월 1, 2025에 액세스, https://vertexeng.com/insights/silica-dust-how-to-reduce-remediate-the-health-risk-it-presents-on-construction-sites/
  62. The Role of Hepa Vacuum Systems in Construction Efficiency - iQ Power Tools, 9월 1, 2025에 액세스, https://iqpowertools.com/blogs/news/hepa-vacuum-construction-efficiency
  63. 인쇄된 콘크리트 청소 : 핵심 사항, 조언 및 주의 사항 - Topciment, 9월 1, 2025에 액세스, https://www.topciment.com/ko/nyuseu/cheongso-inswae-konkeuliteu-ki-joeon-mich-juyisahang
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  67. 콘크리트 표면강화제 씨카플로어 큐어하드24(액상하드너) - 새현산업 - 티스토리, 9월 1, 2025에 액세스, https://saehyun.tistory.com/entry/%EC%BD%98%ED%81%AC%EB%A6%AC%ED%8A%B8-%ED%91%9C%EB%A9%B4%EA%B0%95%ED%99%94%EC%A0%9C-%EC%94%A8%EC%B9%B4%ED%94%8C%EB%A1%9C%EC%96%B4-%ED%81%90%EC%96%B4%ED%95%98%EB%93%9C24%EC%95%A1%EC%83%81%ED%95%98%EB%93%9C%EB%84%88
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  72. How to Stop Concrete Dusting of your Garage Floor, 9월 1, 2025에 액세스, https://allgaragefloors.com/stop-concrete-garage-floor-dusting/
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  74. 콘크리트 표면에 대해 알아야 할 모든 것 - Kangfeides, 9월 1, 2025에 액세스, https://kabrasives.com/ko/blog/%EC%BD%98%ED%81%AC%EB%A6%AC%ED%8A%B8-%ED%91%9C%EB%A9%B4%EC%97%90-%EB%8C%80%ED%95%B4-%EC%95%8C%EC%95%84%EC%95%BC-%ED%95%A0-%EB%AA%A8%EB%93%A0-%EA%B2%83/
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