Opportunistic premise plumbing pathogens : a potential health risk in water mist systems used as a cooling intervention

Water mist systems (WMS) are used for evaporative cooling in public areas. The health risks associated with their colonization by opportunistic premise plumbing pathogens (OPPPs) is not well understood. To advance the understanding of the potential health risk of OPPPs in WMS, biofilm, water and bioaerosol samples (n = 90) from ten (10) WMS in Australia were collected and analyzed by culture and polymerase chain reaction (PCR) methods to detect the occurrence of five representative OPPPs: Legionella pneumophila, Pseudomonas aeruginosa, Mycobacterium avium, Naegleria fowleri and Acanthamoeba. P. aeruginosa (44%, n = 90) occurred more frequently in samples, followed by L. pneumophila serogroup (Sg) 2–14 (18%, n = 90) and L. pneumophila Sg 1 (6%, n = 90). A negative correlation between OPPP occurrence and residual free chlorine was observed except with Acanthamoeba, rs (30) = 0.067, p > 0.05. All detected OPPPs were positively correlated with total dissolved solids (TDS) except with Acanthamoeba. Biofilms contained higher concentrations of L. pneumophila Sg 2–14 (1000–3000 CFU/mL) than water samples (0–100 CFU/mL). This study suggests that WMS can be colonized by OPPPs and are a potential health risk if OPPP contaminated aerosols get released into ambient atmospheres

Biological hazards

Biological hazards in the workplace have been a topic of study, discussion and publications for many centuries. Notable early works include Bernado Ramzinni's 18th-century treatise on occupational diseases, De Morbis Artificum Diatriba; John Tyndall's (1888) Essays Oil the Floating-Matter of the Air: In Relation to Putrefaction and Infection; and Dangerous Trades (Oliver 1902). In our own time, outbreaks of SARS and avian flu, anthrax mail attacks, post-Hurricane Katrina mould investigations and other events involving biological hazards have led to an increased awareness of such hazards among occupational hygienists (Esswein etal. 2004; Halpin 2005; Schwab eral. 2007; Thrasher & Crawley 2009). However, there are still many areas in which our knowledge of biological hazards is limited, and there is still research to be done. In particular, complications in the relating of exposure levels to recognisable health effects, and limited knowledge on exposure-response pathways, inhibit the development of exposure standards for many biological hazards. Assessment of biological hazards is a challenging area of occupational hygiene, and this chapter presents an introductory overview of the subject

Assessment of worker exposure to occupational organic dust in hemp processing facility

The cultivation and processing of hemp (Cannabis sativa L.) is a developing industry in Australia. During processing, workers exposed to hemp dust commonly suffer from airway inflammatory response and respiratory disease leading to decreased lung function over time. There is a scarcity of empirical evidence on the respirable fraction of dust concentrations in hemp processing, and no specific guidance material for producers. Determine the relevancy of current health based occupational exposure limits (inhalable/respirable) for protecting workers exposed to hemp based inhalable dusts. Objectives: Measure exposures of workers to airborne hemp dust. Determine potential exposures and compare against published exposure standards. Based on the outcomes of exposure assessment, make recommendations for appropriate control measures. Methods: Both personal and static monitoring will be performed at a hemp processing facility in Victoria, Australia. Analysis will be undertaken using IHSTAT. Differences between inhalable and respirable airborne dust concentrations will be tested using ANOVA and Shapiro-Wilks post-hoc testing. Results: The hemp industry requires a distinct exposure standard and published guidance material to ensure adverse health effects are minimal. Further research is needed on the impacts of respirable fraction of cannabis particulates and their role in respiratory response and disease. This paper will present the findings for innovative field work the first of its kind undertaken in Australia

Biological hazards

Biological hazards in the workplace have been a topic of study, discussion and publications for many centuries. Notable early researchers and their works include Bernadino Ramazinni’s (2001) eighteenth-century treatise on occupational diseases, De Morbis Artificum Diatriba [Disease of Workers], John Tyndall’s (1888) Essays on the Floating-Matter of the Air: In Relation to Putrefaction and Infection; and Thomas Oliver’s (1902) Dangerous Trades: The Historical, Social, and Legal Aspects of Industrial Occupations as Affecting Health. Biological hazards such as viruses, bacteria and allergens exert a significant burden on worker health and wellbeing, as well as impacting the economy. Between 2014 and 2015, infections and parasitic disease caused 290 serious workers’ compensation cases (0.2 per cent of all claims), while injuries and illnesses associated with biological factors ranged from 606 cases in 2000-01 down to 360 cases in 2012-13 (Safe Work Australia, 2018). Industries with elevated risk of biological exposures—particularly those relating to micro-organisms—include health care, agriculture, waste management, forestry and food production (Safe Work Australia, 2018; Viegas et al., 2017). Consideration should also be given to previously unquantified biological hazards, whether these are atmospheres such as space (Lang et al., 2017), evolving ecosystems due to climate change, such as permafrost melt and anthrax (Charlier et al., 2017), or emergent industries such as medicinal and recreational cannabis production (Davidson et al., 2018; Green et al., 2018)

Health risks associated with the use of water mist systems as a cooling intervention in public places in Australia

The exposure of people to opportunistic premise plumbing pathogens (OPPPs) such as Legionella, Mycobacterium, and Pseudomonas in aerosolized water has been linked to opportunistic infections. Water mist systems (WMS) that are used to cool public places by flash evaporation of tiny water aerosols are gaining prominence in regions with hot climates in Australia. The potential of WMS to be colonized by OPPPs has not been adequately studied. The public health impact of OPPPs is significant, as Legionella accounted for 66% of waterborne disease outbreaks associated with drinking water systems in the U.S. in 2013–2014. Legionella infections caused by the inhalation of contaminated water aerosols in Europe increased from 1,161/year in 1994 to 4,546/year in 2004. As WMS are part of premise plumbing, they have structural characteristics that promote biofilm formation, growth of free-living amebae, inadequate disinfection levels, elevated water temperatures, and oligotrophic conditions—all of which promote OPPP inhabitancy. This special report highlights the potential public health risks of using WMS as a cooling intervention in public places and advocates for their regulation in places of public assembly and entertainment

Evaluation of the impact of indoor smoking bans on air quality in Australian licensed clubs

The quality of indoor air in Australian buildings is unknown due to limited published data. The assessment of indoor air quality (IAQ) in hospitality environments is of special concern because they are frequented by sensitive populations such as the elderly, children, and people with pre-existing health conditions, who may be at risk of developing adverse health reactions if the IAQ is poor. As of 2010, all Australian states and territories have introduced legislation banning smoking in enclosed public places, including licensed clubs

More than silica : exposure of stonemasons to volatile organic compounds

Introduction: Artificial stone (AS) is widely recognised as a signif- icant source of occupational respirable crystalline silica (RCS) exposure. However, stonemasons may also be exposed to noise, vibration and chemicals that could have additive or synergistic effects in combination with RCS. The aim of this project was to evaluate stonemason exposure to volatile organic compounds (VOCs)

Evaluation of the NIOSH BC-251 personal bioaerosol sampler for sampling viable and culturable pathogenic bacteria

Objective: Evaluation of the NIOSH BC-251 personal bioaerosol sampler for the collection of viable and culturable pathogenic bacteria in liquid. Methods: The NIOSH BC-251 sampler was loaded with 7mL of resuscitation buffer (polyethylene glycol 8000, peptone and Tween 20) in the 15 mL centrifuge tube; 1mL of resuscitation buffer in the 1.5 mL centrifuge tube; and a gelatin filter in the 37 mm filter cassette. The SKC Biosamplers were filled with 20 mL of resuscitation buffer. Duplicate samples were collected over a 4 hour period with both samplers in 4 dairies between June and August 2012. Swab samples were also collected from the hygiene station, disinfectant barrell (center aisle) and the parlor wall directly underneath milking stalls at each dairy. Samples and media were transported on ice. 100uL aliquots of samples and/or sample dilutions were inoculated onto chromogenic agar (E. coli 0157, Salmonella and Rapid L mono) for counting, and presumptive identification of pathogenic bacteria. Suspect colonies were isolated on to Tryptic Soy Agar to obtain pure cultures, gram stained and ribotyped with the DuPont Qualicon Microbial Characterization System. Results: The NIOSH BC-251 samplers had a significant reduction in evaporation losses in comparison to the SKC biosamplers. Viable and culturable bacteria, in particular gram-negative speces, were collected by both samplers and included; Escherichia coli, Stenotrophomonas maltophilia, Citrobacter ferundii, Enterobacter sp. and Pseudomonas sp. E. coli 0157:H7, Salmonella sp. or Listeria monocytogenes where not detected in either the air or swab samples. Conclusions: The NIOSH BC-251 sampler is a portable, durable and discrete bioaerosol sampler which could make an ideal replacement for glass impingers in food production facilities where broken glass can present a significant hazard for food safety. Research is underway to assess any variation in the particle collection efficiency of the BC-251 from the addition of a liquid into the sampling system

Extraction of RNA from rhino-probe samples : the good, the bad and the ugly

Rhino‐probe™ nasal curettes have been utilized in recent clinical studies to obtain mucosal epithelial cells for in‐vitro studies on the pro-inflammatory effects of diesel exhaust and tobacco smoke. The curettes have been reported to give more consistent sample collection, as well as higher cell numbers of cells than traditional approaches (cytology brushes/lavage). The aim of this study was to develop a Ribose Nucleic Acid (RNA) extraction method for Rhino‐probe™ nasal mucosal cell samples stored in RNAlater. This method will be applied in a study of inflammatory markers in Colorado dairy workers. Nasal epithelial cells were taken from the inferior turbinate with Rhino‐probes™. The samples were transferred to RNAlater and stored at ‐74°C. To process; 500μL of PBS was added, and the samples pelletized by centrifuging. The supernatant was removed and either RLT buffer (Qiagen) or Trizol (Life Sciences) added. The tissues were homogenized for 30s with a motorized pellet pestle. Four RNA extraction methods were tested. Extraction with the RNeasy kit, RNeasy Micro kit and TRIzol, as well as a two‐step homogenization (pestle and QIAshredder) combined with Micro RNeasy kit. A subset of samples were collected and frozen in RLT buffer. These samples were extracted with the RNeasy Micro kit, with and without the QIAshredder step. RNA quantified with a NanoDrop Spectrophotometer. The combination of tissue storage in RLT buffer with two‐step homogenization method provided RNA with the highest concentration and purity, followed RNAlater samples extracted by the same method. RNA yields from the TRIzol method were highly variable and of poor quality. The RNeasy kit yielded very little RNA. The RNAlater is attributed to poor RNA yield due to its viscosity. This viscosity inhibits pellet formation, even with the addition of PBS, leading to sample loss and transfer of RNAlater residue to extraction columns. It is recommended that Rhino‐Probe samples are stored in RNA lysis buffer and snap frozen in the field with dry ice or a freezer cube. For optimal RNA, samples should be processed with commercial extraction kits designed for small tissue quantities and incorporate a two‐step homogenization process such as the pestle and QIAshredder combination

Dust diseases in modern Australia : a discussion of the new TSANZ position statement on respiratory surveillance

New measures are designed to improve health outcomes for workers in the coal mining, artificial stone and other dust-generating industrie