Identifying and Mitigating Vapor Intrusion Risks for Building Occupants

Vapor intrusion occurs when vapor-forming chemicals migrate from a subsurface source into an overlying building. The subsurface source is typically contaminated soil and/or groundwater. These vapor-forming chemicals can cause indoor air quality (IAQ) problems and sometimes pose a health concern for building occupants.

Examples of vapor-forming chemicals listed by the U.S. Environmental Protection Agency (EPA) include:

• Volatile organic compounds (VOCs), such as trichloroethylene and benzene.
• Select semi-volatile organic compounds (SVOCs), such as naphthalene.

The agency goes on to warn that in extreme cases, the vapors may accumulate in dwellings or occupied buildings to levels that may pose:

• Near-term safety hazards (e.g., explosion).
• Acute health effects.

“Vapor intrusion of soil vapors, from naturally occurring methane to synthetic chemicals into the built environment, is a concern to occupant health. These unwanted compounds can result in acute occupant exposure to high concentrations over short periods and/or chronic exposure to low concentrations over extended period. Both acute and chronic chemical exposure may pose an unacceptable risk of health effects,” said Jeff Bannon, PG, Vice President of Environmental Services for Clark Seif Clark, Inc. (CSC). “Creating a sampling plan, executing that plan, interpreting the results, and assessing occupant risk over both the short and long-term requires consideration of numerous factors. Consideration is given to chemicals used and stored in the structure, building activities, type and concentration of compounds in soil beneath the structure, ventilation, building pressures, and much more. At CSC, our expert staff can identify vapor intrusion risks utilizing the most advanced testing methods, monitoring instruments, and decades of experience. If vapor intrusion issues are found, there are mitigation techniques that can be implemented to improve indoor conditions.”

CSC recently sponsored an educational video about vapor intrusion and indoor air quality that can be seen below.

To learn more, visit www.csceng.com or call 800-807-1118.  

CDC Offers Action Items to Reduce Infection Risks in Schools

In May, the Centers for Disease Control and Prevention (CDC) announced the release of new guidance for preventing the spread of infections in K-12 schools. The agency shared various everyday actions that schools can take to help keep students healthy by mitigating the spread of infections. 

The five actions listed by the CDC are:

1. Taking steps for cleaner air.
2. Cleaning, sanitizing, and disinfecting.
3. Hand washing.
4. Respiratory etiquette.
5. Vaccinations.

Cleaner air can reduce the likelihood of spreading disease, particularly respiratory viruses. Strategies listed by the CDC to achieve this include:

• Ensuring existing HVAC systems are providing outdoor air in accordance with ventilation design codes.
• Considering ventilation design and/or enhancements when remodeling or constructing new buildings to optimize clean air.
• Opening windows, when doing so does not create a safety hazard, to increase ventilation.
• Using portable air cleaners in spaces with low ventilation.

Infection prevention can be as simple as conforming with the design occupancy rate by ensuring no more students occupy a space than the system was designed to handle. Infection prevention can also be complicated, such as struggling to identify the target pathogen, choosing target-appropriate disinfectant for pathogens of concern, mixing cleaning and disinfecting agents according to the manufacturer’s specification, applying agents in compliance with the EPA registration requirements for precleaning, dwell time, rinsing, etc. 

To assist in these efforts, the infection control, industrial hygiene, and indoor environmental quality experts at CSC offer school building assessments and inspections; HVAC system evaluations; 3rd party confirmation of cleaning and disinfection protocols; and air, surface, and water testing for environmental pathogens. These resources support programs by schools and universities to protect their students, teachers, and staff. CSC even provides training services for school administrators and facility managers to help ensure they have the knowledge and tools to optimize indoor conditions in the classroom and other educational facilities.” 

CSC also recently sponsored an educational video sharing the CDC’s everyday action items for schools to prevent and control the spread of infections. It can be seen below.

To learn more, visit www.csceng.com or call 800-807-1118.