Airborne Pathogens inside Automobiles for Domestic Use: Assessing In-Car Air Decontamination Devices Using Staphylococcus aureus as the Challenge Bacterium

ABSTRACT Family cars represent ∼74% of the yearly global output of motorized vehicles. With a life expectancy of ∼8 decades in many countries, the average person spends >100 min daily inside the confined and often shared space of the car, with exposure to a mix of potentially harmful microbes. Can commercial in-car microbial air decontamination devices mitigate the risk? Three such devices (designated devices 1 to 3) with HEPA filters were tested in the modified passenger cabin (3.25 m3) of a four-door sedan housed within a biosafety level 3 containment facility. Staphylococcus aureus (ATCC 6538) was suspended in a soil load to simulate the presence of body fluids and aerosolized into the car's cabin with a 6-jet Collison nebulizer. A muffin fan (80 mm by 80 mm, with an output of 0.17 m3/min) circulated the air inside. Plates (150 mm diameter) of Trypticase soy agar (TSA), placed inside a programmable slit-to-agar sampler, were held at 36 ± 1°C for 18 to 24 h and examined for CFU. The input dose of the test bacterium, its rate of biological decay, and the log10 reductions by the test devices were analyzed. The arbitrarily set performance criterion was the time in hours a device took for a 3-log10 reduction in the level of airborne challenge bacterium. On average, the level of S. aureus challenge in the air varied between 4.2 log10 CFU/m3 and 5.5 log10 CFU/m3, and its rate of biological decay was −0.0213 ± 0.0021 log10 CFU/m3/min. Devices 1 to 3 took 2.3, 1.5, and 9.7 h, respectively, to meet the performance criterion. While the experimental setup was tested using S. aureus as an archetypical airborne pathogen, it can be readily adapted to test other types of pathogens and technologies. IMPORTANCE This study was designed to test the survival of airborne pathogens in the confined and shared space of a family automobile as well as to assess claims of devices marketed for in-car air decontamination. The basic experimental setup and the test protocols reported are versatile enough for work with all major types of airborne human pathogens and for testing a wide variety of air decontamination technologies. This study could also lay the foundation for a standardized test protocol for use by device makers as well as regulators for the registration of such devices.

The Fe-Male Spaces of Modernism: A Western Canadian Perspective

The Provision of improved facilities for women in domestic space and their increased participation in the design process were material aspects of the Modern movement in architecture. While initially directed toward the provision of improved conditions for lower-income families, the main outcome would occur in postwar middle-class housing, particularly in North America. This outcome was associated with a renewal of conservative suburbanization and populist capitalism. The consequences of these design and socioeconomic practices – especially as demonstrated in that significant liminal space between theorized professional production and anecdotal public consumption – for the reinscription of women's presence in domestic space was therefore of considerable import. Scholarly attention has concentrated on the architectural consequences of revised gender relations and on the activity of women designers and architectural writers. This essay seeks to advance discussion of those consequences and activities by means of a situated approach that is centered on a multivalent analysis of the supposed inscription and representation of the modern woman in the Modernist suburban home. The site is the rapidly expanding but physically, socioeconomically, and culturally discreet North Shore area of Vancouver, 1945–65. The location typifies the resuscitation of the middle-class suburb through what might be termed Automod-ernism. The extension of North American trends such as the individual family automobile and home ownership reinforced by laborsaving appliances became a distinct phenomenon of the Modern movement. The time frame corresponds with the postwar baby boom and sustained economic and demographic growth, when child rearing generally kept women, especially of middle-income families, mostly at home.

Pediatric Emergency Transport and the Private Practitioner

A mail survey of 182 pediatricians and 92 family practitioners in Pennsylvania was conducted to determine their methods of transport of seriously ill children from their offices to referral centers and their involvement with professional transport services. Although most physicians (93.1%) stated that they had professional services available to them (at their office location), more than half (53.8%) indicated that the patient's family automobile was their most commonly used method of transport of ill children to tertiary care centers. This was true regardless of the disease entity involved, including suspected epiglottitis. Practice setting had little influence on transport method. However, in general, younger children were judged to need ambulance transport more often than older children. Reasons cited for not using professional transport from the office included a perceived better efficiency of the family car (61.8%), the prohibitively high expense of professional transport (9.8%), and failure to consider professional transport (6.5%). Further study of this component of office preparedness is suggested.

Questions Car Safety Statistics

I was disappointed at the editorial decision to publish the paper by Dr. Kanthr, "Car Safety for Infants: Effectiveness of Prenatal Counseling" (Pediatrics 58:320, September 1976). Dr. Kanthor himself must have realized that the differences between his counseled and noncounseled group in the proportion of children being adequately restrained in their family automobile at the six-week well-child visit did not reach statistical significance (df = 1, χ2 = 1.527, .2 < P < .3). He justifiably claimed that the results suggested only a trend, but he did claim that the differences observed in the two groups resulted from the single counseling session.

Factors Moderating the Resolution of Preference Conflict in Family Automobile Purchasing

A comparison of husbands’ and wives’ preferences in 11 subdecisions of the automobile purchase decision revealed strong similarity in first choices but moderate discrepancy in total preference distributions. However, analysis of responses to measures of involvement, empathy, and recognized authority supports the hypothesis that these factors may reduce substantially the likelihood of conflict-resolving behavior, thus suggesting the need to add these variables to models of family decision making.