In 1985, 362 primary schoolchildren and their 319 mothers were surveyed in Hong Kong to study the possible relationship of air pollution to respiratory illnesses. Using nitrogen dioxide (NO2) measured by personal samplers as a measure of air pollution, the study aimed to identify the major sources of NO2 in the indoor environment and see whether its increased presence was associated with respiratory symptoms. The levels of NO2 among the mothers was found to increase by 21% if dust exposure was reported from the workplace, 18% if they used such cooking fuels as liquid petroleum gas or kerosene, 11% when kitchens did not have ventilating fans, and 10% when incense was burned at home. In terms of respiratory symptoms, an increase in NO2 levels of 19% was reported among those with allergic rhinitis and 18% among those with chronic cough. The levels of NO2 among children were correlated with levels measured in classrooms, all of which had opened windows so that the NO2 came from outdoors. No association was found between children's NO2 levels and respiratory symptoms. With the exception of smoking by the father and the children's NO2 levels, no association was found between smoking at home and NO2 levels.

Personal exposure to nitrogen dioxide and its association with respiratory illness in Hong Kong.

The concentration of carcinogens in the airborne dust of 33 homes in Hong Kong was studied to identify the sources and measure the amounts of 7 polynuclear aromatic hydrocarbons (PAH) including benzo(a)pyrene. The 24 hr samples were collected from kitchens and living rooms of working class homes and analyzed by HPLC. The mean levels of PAH in air and dust were comparatively low, with cooking fires and incense associated with significant increases, and window ventilating fans with significant decreases in PAH concentrations. Perceived pollution sources like water heaters, cigarette smoke, and stir‐fry cooking, led to reduced airborne PAH levels because human responses to these emission sources were to increase natural and mechanical ventilation. The data indicated that compensation behaviours can over‐ride the effects of emission sources, and help explain why measures of increased ventilation from open windows and doors were generally associated with higher PAH levels. The results of this study sh...

Carcinogens in the indoor air of Hong Kong homes: Levels, sources, and ventilation effects on 7 polynuclear aromatic hydrocarbons

The air, particularly the indoor air, contains a considerable burden of unwanted pollution. Overall there may be thousands of pollutants. They are brought in with the outside air or are generated from

Health Risks from Indoor Air Pollutants: Public Alarm and Toxicological Reality

A highly sensitive mutation assay for indoor mutagenicity monitoring was investigated by a combination of Salmonella typhimurium YG strains and the microsuspension method. Tester strains were YG1024, YG1029, YG1041 and YG1042. YG1041 gave the highest sensitivity in the mutagenicity test for the extracts of airborne particulates. The sensitivity of the microsuspension assay using S.typhimurium YG1041 in the absence of S9 mix was approximately 200 times higher than that of the preincubation assay using strain TA98, which has been widely used for mutagenicity monitoring of airborne particulates outdoors. Furthermore, a significant correlation was observed between mutagenicities determined by the microsuspension assay using S.typhimurium YG1041 and TA98, where mutagenicity assay was carried out for airborne particulates collected by a high volume sampler for 24 h every 12 days for 1 year. This new method was also useful for indoor mutagenicity monitoring in which a small amount of airborne particulates was collected by a low noise sampler for 12 h each of 6 consecutive days. The monitoring showed that mutagenicity in the daytime is generally higher than that in the night and that smoking is an important factor in increasing mutagenicity in indoor air.

Highly sensitive mutation assay for mutagenicity monitoring of indoor air using Salmonella typhimurium YG1041 and a microsuspension method

The lung cancer mortality rate has been steadily increasing in industrialized countries of the world. There are many risk factors for the lung cancer induction in our environments. Airborne carcinogens and mutagens are considered to be one of the major risk factors. However, quantitative contribution of airborne carcinogens and mutagens to the lung cancer induction has not yet been accurately evaluated, because of the lack of data on long-term human exposure to these chemicals in many areas which are in different pollution levels. For this purpose, there is an urgent need to develop methodologies suitable for monitoring long-term exposure to these carcinogens and mutagens.

Tadashi Mori

Papers

A Comparison Study on Personal Exposure to Nitrogen Dioxide in Tokyo, Bangkok and Manila

Effect of Various Living Environments on Personal Exposure Levels of Nitrogen Dioxide

A Simple Method for Analysis of Nicotine in indoor Environment

Influence of Sampling Filter on Determination of Anions in Airborne Particulates

Analytical Method of N-Nitrosamines in Side-Stream of Cigarette