This study is about the effectiveness of the indicated ventilation measures in the day-to-day operations of three types of hospitality businesses:
- a pub not serving meals (drinking pub)
- a pub serving full meals (dining pub)
- a discotheque
For effectiveness of ETS reduction, the decision was made to use localised displacement ventilation. Each of the three hospitality businesses has successfully installed and put into use a displacement ventilation system. The systems have been designed so that they meet the aesthetical, fire safety, robustness and comfort requirements for each specific hospitality businesses.
The discotheque has a horizontal displacement system mounted in the sidewall that provides protection on the dance floor. No physical separation has been provided and smoking is permitted everywhere. In addition to fine dust (PM2.5), measurements were conducted for volatile organic components (TVOC) and aldehydes. The other two hospitality businesses each have a localised displacement ventilation system installed below the ceiling. Air is blown from the ceiling of the eating pub and the drinking pub over a limited surface area of 14 and 21 m², respectively. Compartmentalisation is achieved by this directed airflow without any physical separation. A tracer gas was used instead of TVOC and aldehyde to determine the reduction of gaseous components.
Reduction is achieved in two manners. Firstly, a reduction of 80 to 90% in relation to a reference point in the rest of the space is achieved locally in the area around the displacement ventilation system. Secondly, the displacement ventilation system provides additional ventilation in relation to the existing situation so that concentrations at the reference point drop proportionally.
Table 1: Reduction percentages (*Smokers and non-smokers mixed in the protected area)
The results in the table show the exposure reduction rates of gaseous and solid components in a situation where ETS is the main source of these components. This situation existed in the discotheque, for example, where a relatively high number of people were smoking. Lower reduction rates were measured for fine dust (PM2.5) in the dining and drinking pubs. This is due to the fact that localised displacement reduced the concentrations of fine dust to such an extent that other sources of fine dust, such as clothing, and the supply of fine dust via the ventilation system become more relevant than tobacco smoke.
The reduction rates in Table 1 are in agreement with the predictions described in Attachment 2 to the RIVM/TNO report , which predicts a reduction rate of 92% based on a review of literature and a ventilation model. It is emphasized that these reduction rates apply to the situation without any physical separation between smokers and non-smokers. Reduction rates of higher than 99% are possible with a physical separation, e.g. in the form of a glass wall in a restaurant.
This report shows possible solutions to reduce exposure to ETS in the hospitality industry. If the Occupational Health and Safety Act had been strictly complied with, creating a smoke-free zone around the servers would have been sufficient. However, from the perspective of general public health in the Netherlands, it makes more sense to seek to reduce exposure for servers and visitors. This is particularly true because visitors widely outnumber servers. This viewpoint has resulted in the following plans:
- In the drinking pub visitors and servers are protected;
- In the discotheque primarily the visitors on the dance floor are protected; and
- In the dining pub primarily the visitors under the downflow are protected.
In all three cases, the increased level of ventilation also has a positive effect on the exposure of servers.