Acid fog: effects on respiratory function and symptoms in healthy and asthmatic volunteers

Journal Article · Tue Jan 31 23:00:00 EST 1989 · Environ. Health Perspect.; (United States)

DOI:https://doi.org/10.1289/ehp.8979159· OSTI ID:6071536

Hackney, J D; Linn, W S; Avol, E L

Acidic air pollutants generally are dissolved in water droplets. Mean droplet diameter may range from more than 10 microns in dense fog to less than 1 micron at low relative humidity. Droplet size influences the deposition of inhaled acid within the respiratory tract and thus may influence toxicity. To help assess health risks from acid pollution, we performed controlled exposures of normal and asthmatic volunteers to sulfuric acid aerosols at nominal concentrations of 0 (control), 500, 1000, and 2000 micrograms/m/sup 3/. Exposures lasted 1 hr with intermittent heavy exercise. Response was assessed by lung function tests and symptom questionnaires. Under foggy conditions (mean droplet size 10 microns, temperature 50 degrees F), no marked effects on lung function were found. However, both normal and asthmatic subjects showed statistically significant dose-related increases in respiratory symptoms. In a separate study, normal subjects exposed at 70 degrees F with mean droplet size 0.9 microns showed no marked effect on function or symptoms. Asthmatics showed dose-related decrements in forced expiratory performance and increases in symptoms, most obvious at 1000 and 2000 micrograms/m/sup 3/. The different results of the two studies probably reflect an influence of droplet size, but further investigation is needed to confirm this. The aggregate results suggest that only mild, if any, short-term respiratory irritant effects are likely at acid concentrations attained in ambient pollution.

• Research Organization: Univ. of Southern California School of Medicine, Downey (USA)
• OSTI ID: 6071536
• Journal Information: Environ. Health Perspect.; (United States), Journal Name: Environ. Health Perspect.; (United States) Vol. 79; ISSN EVHPA
• Country of Publication: United States
• Language: English

Related Subjects

550900 -- Pathology
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACID RAIN
AEROSOLS
AIR POLLUTION
ANIMALS
ASTHMA
ATMOSPHERIC PRECIPITATIONS
BODY
COLLOIDS
DISEASES
DISPERSIONS
DOSE-RESPONSE RELATIONSHIPS
DYNAMIC FUNCTION STUDIES
EXERCISE
FOG
HAZARDS
HEALTH HAZARDS
HUMIDITY
HYDROGEN COMPOUNDS
INHALATION
INORGANIC ACIDS
INTAKE
LUNGS
MAMMALS
MAN
ORGANS
PARTICLE SIZE
POLLUTION
PRIMATES
RAIN
RESPIRATORY SYSTEM
RESPIRATORY SYSTEM DISEASES
RISK ASSESSMENT
SIZE
SMOG
SOLS
SULFURIC ACID
SYMPTOMS
TOXICITY
VERTEBRATES