Indoor Air Quality on Passenger Ships

Abstract

Generally, shipboard air quality problems are not severe in comparison to those in many homes and offices. However, a number of problems have been identified which warrant attention in order to safeguard passenger comfort and health. The HVAC systems of some ships, particularly older vessels, are prone to microbial contamination. A lack of awareness of the potential problems at the design stage and subsequent lack of maintenance has allowed moulds and fungi to infiltrate the HVAC system where these collect and grow. These microbes not only pose an immediate risk of respiratory illness and allergic responses, they are also a nuisance with respect to the general maintenance and cleaning of vessels and hence are often a cause of complaint. Airborne microbial sampling has been used extensively to determine the potential for passenger exposure to this type of contamination. Due to the complexities of shipboard HVAC design, proper filtration offers the best method of keeping the system clean and preventing the accumulation of microbial contamination. Ventilation efficiency is a problem on some vessels, especially in smaller cabins or densely occupied communal areas. Thermal comfort is also a source of complaint which requires attention on many ships. Proactive monitoring to evaluate indoor air quality and identify remedial measures reduces the likelihood of problems developing. Cost-effective improvements can be made to the design and operation of ventilation systems that reduce contamination and improve air quality. It is apparent that many of the problems encountered could have been “designed out”. In particular, attention should be paid to the prevention of ingress of water into the supply and exhaust systems, thereby restricting the potential for microbial proliferation. Provision of better access for inspection and cleaning of ductwork would also be beneficial.