Identify typical sources of VOCs in buildings and practical strategies to reduce exposure.

• A. Only outdoor sources; mitigated by sealing building.
• B. Natural sources only; not manageable.
• C. Releases from manufacturing plants outside building; mitigate by filtration.
• D. Source examples include cleaning products, paints, solvents, and office equipment; strategies include using low-VOC products, improving ventilation, and rapid source removal.

Answer: (D)

VOC emissions in indoor spaces mainly come from everyday products and activities found inside the building. Items like cleaning agents, paints, solvents, and even office equipment release volatile organic compounds into the air as they off-gas at room temperature. Because people spend most of their time indoors, addressing these emissions directly has a big impact on exposure.

This option is the best because it identifies realistic, common indoor sources and pairs them with practical ways to reduce exposure. Using low-VOC products lowers the amount of VOCs released in the first place. Improving ventilation helps dilute and remove VOCs that are already present, speeding up the replacement of indoor air with cleaner outdoor air. Rapid source removal means promptly stopping or minimizing emissions when a product is used or a spill occurs, such as closing containers, properly storing materials, or replacing a high-emission product with a lower-emission one. Together, these strategies target both emission control and air quality management inside the building.

Other options miss the mark by implying VOCs come only from outdoor or natural sources or by suggesting a single, less effective mitigation approach. Sealing the building to address outdoor sources ignores indoor emissions, and focusing only on outdoor sources overlooks the major indoor contributors. Treating all VOCs as natural and not manageable is inaccurate, since many indoor VOCs are anthropogenic and controllable through product choices and ventilation. Filtration or outdoor-source focus alone also doesn’t address the broader range of indoor, easily controllable sources and strategies.