Vomit particles, often microscopic, can become airborne during an emetic event, posing a concern for indirect disease transmission. These tiny droplets and aerosols can carry pathogens, making their presence in the air a potential health risk. The duration for which they remain suspended is influenced by various environmental and physical factors.
What are Vomit Particles and How Do They Become Airborne?
When vomiting occurs, the expulsion force breaks down the stomach contents into a spray of droplets. These droplets vary in size, ranging from larger, visible specks to microscopic particles. Aerosolization transforms the liquid into fine airborne particles, allowing them to remain suspended in the air.
Smaller, lighter particles, known as aerosols, can stay aloft for extended periods, unlike larger droplets that fall rapidly due to gravity. Research using simulated vomiting devices has directly demonstrated that viruses, such as norovirus, can be aerosolized during such events. These airborne particles can contain infectious agents like viruses.
Factors Influencing Airborne Duration
The time vomit particles remain airborne depends on several environmental and physical factors. Particle size is a primary determinant; smaller aerosols, often less than one micrometer, settle much slower than larger droplets, allowing them to travel further and stay suspended for hours. In contrast, larger droplets, exceeding 50 micrometers in diameter, fall to surfaces almost immediately.
Air movement and ventilation significantly impact airborne duration. Good ventilation systems dilute contaminated air and can reduce particle concentrations. However, air currents can also disperse smaller particles over wider areas, potentially increasing the reach of contamination within an enclosed space. Poorly ventilated environments allow particles to remain suspended for longer periods.
Humidity also plays a role in how long these particles stay aloft. In low humidity conditions, droplets evaporate more quickly, shrinking into smaller, lighter particles that can remain airborne for extended times. Conversely, higher humidity can cause droplets to retain their moisture, making them heavier and prone to settling faster, thus reducing their airborne duration. Additionally, temperature can influence the rate of evaporation, indirectly affecting particle size and settling.
Implications for Contamination and Disease Spread
Airborne vomit particles pose a risk for indirect illness transmission. When inhaled, these tiny particles can introduce pathogens directly into the respiratory system, leading to infection. For example, norovirus, a highly contagious pathogen, can be spread through the inhalation of aerosolized vomit particles. Only a small number of norovirus particles are needed to cause illness.
Particles that settle can contaminate nearby surfaces, creating fomites. Contact with these contaminated surfaces, followed by touching the mouth, nose, or eyes, can also lead to infection. This secondary contamination can extend the reach of an outbreak beyond the immediate area of the emetic event. The resilience of pathogens like norovirus, which can survive on surfaces for days to weeks, emphasizes the potential for widespread contamination.
Mitigation and Cleanup Strategies
Prompt action is important for reducing contamination risk from vomit particles. Immediately increase ventilation by opening windows and using fans to disperse and dilute airborne particles. Moving individuals away from the affected area also minimizes exposure.
When cleaning, wear personal protective equipment (PPE), such as disposable gloves, masks, and aprons, to prevent direct contact and inhalation. Cover the vomit with absorbent material like paper towels or kitty litter, then carefully scoop and seal it in a plastic bag. After removing the bulk material, wash all contaminated hard surfaces with soapy water, followed by disinfection with an appropriate cleaning agent.
For effective disinfection against pathogens like norovirus, a fresh chlorine bleach solution (e.g., 5 to 25 tablespoons of household bleach per gallon of water) is recommended, ensuring the surface remains wet for several minutes. Machine-wash contaminated fabrics and clothing with detergent and hot water, with bleach if suitable, and then machine-dry. These steps help minimize illness transmission after a vomiting incident.