The Four Hidden Building Hazards: Addressing Mold, Radon, Asbestos, and Lead
Metric’s Industrial Hygiene and Occupational Safety teams have spent the better part of 35 years inside and outside buildings in the Louisville metro area. Over this time, I’ve been in many buildings—whether residential, commercial, or industrial—that have developed environmental hazards that threaten the health and safety of their occupants. Some of the most common and dangerous of these hazards are mold, radon, asbestos, and lead. These issues often go undetected until they have already caused significant damage to both property and human health. It’s very important to understand these hazards so that you know when to seek professional help to maintain a safe indoor environment.
Mold
One of the hot button issues in Louisville is the presence of mold in many properties. With the recent heavy rains and floods, we have handled more mold issues. Mold is a type of fungus that thrives in damp, humid environments. It often grows behind walls, under floors, or in ceilings after water leaks, poor ventilation, or flooding. While it might appear as a minor nuisance, mold can pose serious health risks. Exposure to mold spores can trigger allergic reactions, asthma attacks, respiratory infections, and even more severe symptoms in individuals with weakened immune systems. Mold is not always visible or easy to detect. Air quality tests and surface sampling can identify hidden colonies and quantify mold spore levels. Early detection prevents further structural damage and protects the health of occupants.
Radon
Radon is a naturally occurring radioactive gas that seeps into buildings through cracks in the foundation, crawlspaces, or basements. It is odorless, colorless, and tasteless, making it undetectable without proper testing. Long-term exposure to high radon levels is the second leading cause of lung cancer in the United States, after smoking.
The only way to know if radon is present is through testing. Our teams measure gas levels over a period of days. The EPA recommends mitigation for radon levels at or above 4.0 picocuries per liter (pCi/L). We conduct accurate tests and design mitigation systems that reduce indoor radon levels, often using ventilation and sealing techniques to prevent gas intrusion
Asbestos
Asbestos was commonly used in building materials such as insulation, floor tiles, roofing, and pipe coatings due to its heat resistance and durability. When materials containing asbestos deteriorate or are disturbed, they release microscopic fibers into the air. Inhalation of these fibers can cause severe health issues, including mesothelioma, asbestosis, and lung cancer.
Asbestos is most dangerous when airborne. If a building was constructed before the 1980s, it’s especially important to test materials before renovations or demolitions. Disturbing asbestos without proper precautions can release harmful fibers.
Only licensed asbestos inspectors and abatement contractors should handle asbestos testing and removal. Our teams follow strict safety protocols when testing for asbestos.
Lead
Lead-based paint was widely used in homes and buildings prior to its ban in
residential use in 1978. Deteriorating lead paint, especially in older structures, produces dust that can be ingested or inhaled. Lead poisoning is particularly dangerous for children, causing developmental delays, learning disabilities, and behavioral issues. In adults, it can lead to kidney damage and high blood pressure.
Lead testing is essential in older buildings, especially before painting, remodeling, or window replacement. Dust wipe sampling, paint chip analysis, and water testing (for lead pipes) are some standard methods we use.
Our teams are highly trained and can evaluate exposure risks and develop a safe plan for removal or containment. Professional abatement ensures compliance with safety regulations and reduces the risk of contamination.
Mold, radon, asbestos, and lead are silent intruders that can seriously compromise the safety and livability of a building. Regular environmental testing is not just a precaution—it’s a necessity for health and safety. Enlisting the expertise of certified environmental professionals ensures that these hazards are identified, managed, and eliminated according to best practices and regulatory standards. By investing in proactive inspections and mitigation, property owners protect not only their investment but also the well-being of everyone who enters the building.
Our firm, Metric Environmental, specializes in Industrial Hygiene services that provide expert guidance on environmental health and safety issues, including emergency response planning, occupational safety inspections, hazard communication, and occupational safety and health.
Welcome Our New Team Members!
2025 Internship!
Join us in welcoming our 2025 Interns Allison Trammell and Kadence Shaner! They will both be working as part of our Cultural Resources team!
Allison is a second-year master’s student in the IU Indianapolis’ Public History Program and will be working with us through next May. She will be assisting the team in doing historical research and writing historical contexts, as well as learning about architectural styles, nomenclature, and other kinds of fieldwork. Her training at IU in conducting historic research and analysis will be especially useful to the CR team.
Kadence is an archaeology graduate student at the University of Indianapolis, where she also recently completed her undergraduate degree. She will be learning the basics of completing archaeological consulting, from records review, to fieldwork, to report writing, as well as the regulations and laws behind our work which include the National Environmental Policy Act, National Historic Preservation Act, and Section 106.
Learn more about our Internship program or investigate a full-time career by viewing our open positions here.
Current State of Wetland Regulations
On March 12, 2025, the U.S. Environmental Protection Agency (USEPA) issued a memorandum on guidance for implementation of the definition of “Waters of the United States” to respond to feedback for clarification on what constitutes a “continuous surface connection” with a Traditional Navigable Water which requires a water resource be subject to Federal regulation under Section 404 of the Clean Water Act (CWA). The intent is to give the U.S. Army Corps of Engineers (USACE) guidance on how to implement the most recent definition of jurisdictional “Waters of the United States” based on the Supreme Court’s decision in Sackett v. Environmental Protection Agency (2023) and Rapanos v. United States (2006).
In Rapanos, Justice Kennedy provided that a “significant nexus” which included evaluation of the existence of a chemical, physical, or biological connection of wetlands to downstream Traditional Navigable Waters, as an appropriate demonstration of jurisdictional connection. However, in Sackett, it was ruled that only wetlands with a “continuous surface connection” to bodies of water that are “Waters of the U.S.” can be considered jurisdictional under the Clean Water Act.
Under Sackett, only wetlands that directly abut, or touch, a “Waters of the U.S.” and maintain a “continuous surface connection” where it is “difficult to determine where the water ends and the wetland begins” can be considered jurisdictional and subject to Section 404 CWA regulations.
So, what does this mean for wetland regulations in the United States? Only intermittent and perennial streams and the wetlands that share a boundary with them are currently subject to protection under the Clean Water Act. Any wetlands outside of this definition are not regulated under federal law and are considered to be isolated wetlands. Some states have laws that provide some protection for wetlands. Indiana is one of the 19 states that has isolated wetland protections (according to the Environmental Law Institute); however, the landscape of those protections has been changing over the last 4 years.
In Indiana, some wetlands that are not regulated under the Federal CWA are subject to regulation under the State Regulated Wetlands Law (also known as the Indiana Isolated Wetlands Law). This law has been in effect since 2004 but has recently undergone changes due to Senate Enrolled Act 389 (SEA 389) which was passed in2021. Isolated wetlands are assigned a classification of Class I, II, or III, with III being the highest quality. Wetland quality is assigned by wetland scientists in the field in conjunction with coordination with IDEM, and considers factors such as amount of human disturbance, plant species diversity, hydrological function, location in the landscape, and significance of the wetland to provide habitat for wildlife.
SEA389 significantly reduced protection for Indiana isolated wetlands in multiple ways. The State Regulated Wetlands Law was changed to provide several increases in exemptions for the number of isolated wetlands that could be impacted by fill without requiring a permit and potential mitigation for loss of wetlands. Those exemptions now include all Class I wetlands regardless of size(previously protected up to certain sizes with mitigation required for higher amounts of impacts); Class II wetlands in rural areas up to 3/8 acre in size; Class II wetlands located within the boundaries of a municipality up to ¾ acre in size; and all voluntarily created wetlands other than mitigation wetlands. Exemptions become more complicated when sites contain more than one Class II wetland and require additional calculations to determine which portion of these wetlands are exempt. Impacts to isolated wetlands outside of the exemptions listed above and all impacts to Class III wetlands still require a State Regulated Wetlands permit.
Indiana has lost 85% of its wetlands since settlement (according to the Indiana Department of Environmental Management). The majority of remaining wetlands in the state, up to 80-90%, are isolated wetlands (Hoosier Environmental Council).These regulation changes will increase the rate of wetland loss at a time when climate change and increases in severe weather are producing increased flooding which these important ecosystems help to regulate. Wetlands have many essential functions in the landscape in addition to flood control, including water quality management and providing critical habitat for many wildlife species including endangered, threatened, and rare species. Changes in federal and state level regulations affect the future existence of this important natural resource and contribute to the loss of critical wetland functions including public health. It will be left up to the public to deal with the consequences of wetland loss that will continue to occur because of these regulation changes. Improvements to infrastructure and the built environment must consider wetlands as an important natural resource to be protected and maintained through conscientious management versus a nuisance and impediment to development.
Our Metric Natural Resources teams have expertise in wetland and stream assessment and mitigation. We assist our clients with understanding and complying with State and Federal Clean Water Act regulations concerning impacts to Waters of the U.S./Waters of the State and in the protection of other precious natural resources.
Metric upholds the value of Integrity as a cornerstone of all we do. As environmental consultants we understand that we play a crucial role in safeguarding human health and the environment by assessing and mitigating the environmental impact of human activities. Integrity is essential in this field because the accuracy and honesty of our assessments directly influence regulatory compliance, corporate decision-making, and the protection of natural resources. Our team of consultants strive to uphold ethical standards that help prevent environmental degradation, ensure transparency in reporting, and build trust among stakeholders, including governments, communities, and clients. We are convinced that without integrity, the credibility of environmental data can be compromised, potentially leading to harmful consequences for the environment and society.