IAQ in the News...

• ASHRAE Position Document on Airborne Infectious Diseases Approved by ASHRAE Board of Directors June 24, 2009
  Executive Summary This position document has been written to provide the membership of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and other interested persons with information on the health consequences of exposure to airborne infectious disease and on the implications of this knowledge for the design, installation and operation of heating, ventilating, and air-conditioning (HVAC) systems. In this paper three methods of transmission of Airborne Infectious Diseases are discussed, namely through direct contact, large droplet contact, and inhalation of droplet nuclei. The practice of the HVAC&R professional is likely limited to reduction of disease transmission to those diseases transmitted by droplet nuclei. The conclusions regarding needed research and advice for the practitioner are listed in Table 1.
  ASHRAE’s sole objective is to advance the arts and sciences of HVAC&R to serve humanity and promote a sustainable world through research, standards writing, publishing and continuing education. Therefore, the health effects of airborne infectious disease transmission are relevant to ASHRAE.
  ASHRAE’s position at the present is:

1. Many infectious diseases are transmitted through inhalation of airborne infectious particles termed droplet nuclei.
2. Airborne infectious particles can be disseminated through buildings including ventilation systems.
3. Airborne infectious disease transmission can be reduced using dilution ventilation, specific in-room flow regimes, room pressure differentials, personalized and source capture ventilation, filtration, and UVGI.
4. ASHRAE should commit to improving the health of individuals who occupy buildings and should support further research on engineering controls to reduce infectious disease transmission.
   

• USA Today: Toxic Air and America's Schools USA Today used an EPA model to track the path of industrial pollution and mapped the locations of almost 128,000 schools to determine the levels of toxic chemical outside. The potential problems that emerged were widespread,insidious and largely unaddressed.
• Medical News Today: Medicare Change Sheds Light On New Infection Precaution Measures As part of Centers for Medicare and Medicaid (CMS) Rule-1553-P, effective October 1, 2008, Medicare will no longer pay for eight conditions that can be acquired by patients during hospital stays that could have been reasonably prevented by following evidence based guidelines. CMS hopes the change will improve accuracy in Medicare's payment under the acute care hospital inpatient prospective payment system (IPPS), while also creating incentives for the healthcare community to improve quality initiatives and patient care.
• University of Bath: MRSA use amoeba to spread, sidestepping hospital protection measures, new research shows Scientists from the University of Bath have shown that MRSA infects and replicates in a species of amoeba, called Acanthamoeba polyphaga, which is ubiquitous in the environment and can be found on inanimate objects such as vases, sinks and walls.

  Invasive Aspergillosis in a Tertiary-Care Hospital in Thailand†To the authors’ knowledge, the present study is the largest study regarding IA in Asian populations and in Thailand. The presented data indicated that IA was common and could cause lethal fungal infection in immunocompromised host and even in a normal host. In clinical practice, there are problems for the IA diagnosis and it remains an underdiagnosed disease.

• Airborne Transmission of MRSA Scientific studies which show evidence of MRSA airborne transmission.
• New York Post: Mold in 20 Hospital Rooms April 23, 2006 -- New York Presbyterian-Columbia detected low levels of a potentially deadly mold in almost 20 rooms at its children's hospital from
  2001 to 2004, according to state records obtained by The Post. The test results released Friday showed traces of aspergillus, a common mold often found in construction dust. While state health officials said the low readings were not considered a threat to patients, a lawyer contended aspergillus at any level can be lethal to kids with weakened immune systems. The revelation comes as three families prepare to sue the hospital for allegedly causing the deaths of their sick children by exposure to aspergillus.

• Metro Spirit: When a hospital gets sick: Our inquiries began more than two years ago, when someone complained to the Metro Spirit that mold in one of the MCG Health buildings was making them ill. MCG Health has not responded to any of our verbal or written requests. However, as records obtained as part of a lawsuit against MCG Health show, workers have complained for years about illnesses that appear to them or others to be related to mold and mildew. The hospital denies it’s a problem. Deborah Humphrey of the MCG Health public information office said the hospital would not grant an interview on the subject because none was needed. “Problem identified, problem solved,” she said. However, Metro Spirit has obtained documents in which a hospital employee has accused MCG Health of having such serious mold and mildew problems that it has contributed to the death of a patient.

• International Health Economics Association: Outbreak of Invasive Aspergillus Infection in Surgical Patients, Associated with a Contaminated Air-Handling System An outbreak of Aspergillus infection at a tertiary care hospital was identified among inpatients who had amputation wounds, peritonitis, allograft nephritis, or mediastinitis. During a 2-year period, 6 patients were identified, all of whom had Aspergillus species recovered from samples from normally sterile sites. All cases clustered in the operating theater during a single 12-day period. To assess operating theater air quality, particle counts were measured as surrogate markers for Aspergillus conidia. A substantial increase in the proportion of airborne particles >3 µm in size (range, 3-fold to 1000-fold) was observed in many operating rooms. A confined space video camera identified moisture and contamination of insulating material in ductwork and variable airflow volume units downstream of final filters. No additional invasive Aspergillus wound infections were identified after the operating theater air-handling systems were remediated, suggesting that this unusual outbreak was due to the deterioration of insulating material in variable airflow volume units.

• AIHA: Controlling Hospital-Acquired Infections Role of Industrial Hygienists Data released by the U.S. National Nosocomial Infections Surveillance System show that every year nearly 2 million patients in North America contract an infection in a hospital and about 100,000 die as a result of their infection. Several outbreaks of hospital-acquired mold infections have been linked with hospital construction, renovation and maintenance, activities that allow mold spores to become airborne. Fungal infections account for 9 percent of all nosocomial infections. Health Canada has carried out an extensive review of literature of nosocomial infections over a 20-year period (1978–1998) and found numerous nosocomial outbreaks related to construction or renovation projects. The NNIS data also show increasing trends in nosocomial fungal infection rates for urinary tract and bloodstream infections and pneumonia in intensive care units.

• Health Complaints in Air Conditioned Buildings Based on an analysis of existing scientific data about Sick Building Syndrome

  Y Dombrowsky and J Hill L.R.I.C

  According to the World Health Organization sick building syndrome (SBS) is an excess of work-related irritations of the skin and mucous membranes and other symptoms, including headache, fatigue, and difficulty concentrating, reported by workers in modern buildings (WHO 83). A prevalence of non-specific health disorders are recorded. Only limited cases of building-related diseases are reported by the medical literature and are usually limited to specific contamination problems (e.g., Legionella released by cooling tower,…).
  SBS may have specific environmental causes in which air-conditioners play a crucial role, and which involve biological contamination. Organic dusts seem to play a major triggering role in indoor health disorders which themselves may fluctuate in accordance with individual susceptibility. It is clearly demonstrated that physical factors like temperature, lighting intensity, etc..., can increase the susceptibility of patients to immunologically active particles through increased stress activity (AIHA 96).

• Isolation of Staphylococcus aureus and Antibiotic-Resistant Staphylococcus aureus from Residential Indoor Bioaerosols
  Angelina Gandara,1 Linda C. Mota,1 Carissa Flores,1 Hernando R. Perez,2 Christopher F. Green,3 and
  Shawn G. Gibbs1 1The University of Texas Health Science Center at Houston, School of Public Health, El Paso, Texas, USA; 2Drexel University, School of Public Health, Philadelphia, Pennsylvania, USA; 3Department of Civil and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio, USA DESIGN: We used Andersen two-stage samplers to collect bioaerosol samples from 24 houses in El Paso, Texas, using tryptic soy agar as the collection media, followed by the replicate plate method on Chapman Stone selective medium to isolate S. aureus. The Kirby-Bauer disk diffusion method was used to determine antibiotic resistance to ampicillin, penicillin, and cefaclor, which represent two distinct classes of antibiotics.
  RESULTS: The average recovered concentration of respirable heterotrophic organisms found outside
  each home was 345.38 CFU/m3, with an average of 12.63 CFU/m3 for S. aureus. The average
  recovered concentration of respirable heterotrophic organisms found inside each home was 460.23
  CFU/m3, with an average of 15.39 CFU/m3 for S. aureus. The respirable S. aureus recovered from
  inside each home had an average resistance of 54.59% to ampicillin and 60.46%. to penicillin.
  Presence of cefaclor-resistant and of multidrug-resistant S. aureus was the same, averaging 13.20%
  per house. The respirable S. aureus recovered from outside each home had an average resistance of
  34.42% to ampicillin and 41.81% to penicillin. Presence of cefaclor-resistant and of multidrugresistant
  S. aureus was the same, averaging 13.96% per house.
  CONCLUSIONS: This study indicates that antibiotic-resistant bioaerosols are commonly found
  within residential homes. Our results also suggest that resistant strains of airborne culturable
  S. aureus are present in higher concentrations inside the study homes than outside the homes.
  

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