Quantitative measurement of airborne cockroach allergen in New York City apartments

Authors

  • W. A. Esposito,

    1. Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA
    2. Present address: Ambient Group Inc, New York, NY, USA
    Search for more papers by this author
  • G. L. Chew,

    1. Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA
    Search for more papers by this author
  • J. C. Correa,

    1. Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA
    2. División de Salud Comunitaria, Fundación Santa Fe de Bogotá, Bogotá, Colombia
    Search for more papers by this author
  • S. N. Chillrud,

    1. Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
    Search for more papers by this author
  • R. L. Miller,

    1. Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA
    2. Division of Pulmonary, Allergy and Critical Care Medicine, Columbia University College of Physicians and Surgeons, NY, USA
    Search for more papers by this author
  • P. L. Kinney

    1. Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA
    Search for more papers by this author

W. A. Esposito
Department of Environmental Health Sciences
Mailman School of Public Health
Columbia University
New York, NY, USA
Tel.: 1 212 944 4615
Fax: 1 212 944 4618
e-mail: wesposito@ambientgroup.com

Abstract

Abstract  We designed and tested a sampling and analysis system for quantitative measurement of airborne cockroach allergen with sufficient sensitivity for residential exposure assessment. Integrated 1-week airborne particle samples were collected at 10–15 LPM in 19 New York City apartments in which an asthmatic child who was allergic to cockroach allergen resided. Four simultaneous air samples were collected in each home: at heights of 0.3 and 1 m in the child’s bedroom and in the kitchen. Extracts of air samples were analyzed by ELISA for the cockroach allergen Bla g2, modified by amplifying the colorimetric signal generated via use of AMPLI-Q detection system (DAKO Corporation, Carpinteria, CA, USA). Settled dust samples were quantified by conventional ELISA. Of the homes where cockroach allergen was detected in settled dust, Bla g2 also was detected in 87% and 93% of air samples in the bedroom and kitchen, respectively. Airborne Bla g2 levels were highly correlated within and between the bedroom and kitchen locations (P < 0.001). Expressed as picogram per cubic meter, the room average geometric mean for Bla g2 concentrations was 1.9 pg/m3 (95% CI 0.63, 4.57) and 3.8 pg/m3 (95% CI 1.35, 9.25) in bedrooms and kitchens, respectively. This method offers an attractive supplement to settled dust sampling for cockroach allergen exposure health studies.

Practical Implications

Until now, cockroach allergen exposures have usually been assessed by collection and analysis of settled dust, on the assumption that airborne cockroach allergen cannot be reliably measured. In this study, a sensitive and quantitative method for measuring indoor airborne exposures to cockroach allergens involving a 7-day integrated total suspended particulate (TSP) sample collected at approximately 10–15 l/min was developed. Investigators are now empowered with an alternative exposure assessment method to supplement their studies and the understanding of allergen aerodynamics in the homes of children with asthma. We report airborne cockroach allergen in apartments, suggesting an ongoing burden of inhalation exposure.

Ancillary