Effect of variation in air conditioner temperature on peak expiratory flow rate of air conditioner users

As a result of increasing environmental temperature, use of air conditioner (AC) has become very popular specially in the urban areas mostly during warmer months of the year. Exposure to cold, dry air of AC on a regular basis can cause various alternations in lung functions of AC users which can lead to many future lung diseases. These alternations in lung functions can be influenced by the temperature at which AC is regulated. This cross-sectional study was conducted to observe the effects of air conditioner use and variation of AC temperature on peak expiratory flow rate (PEFR) of apparently healthy adult male and female living in Dhaka city, Bangladesh. The study group (group A) consisted of 48 apparently healthy adult male and female who were exposed to air conditioner for at least 6 hours per day for minimum 5 days per week for the past 2 to 4 years. They were divided into two subgroups based on temperature at which AC was regulated. Group A1 consisted of 24 subjects (12 male and 12 female) who were exposed to AC for at least 6 hours per day for minimum 5 days per week for the past 2 to 4 years and where temperature of the AC was constantly regulated in between 18° C to 22°C. Group A2 consisted of 24 subjects (12 male and 12 female) who were exposed to AC for the same period of time but where AC was constantly regulated in between 23°C to 25°C. The control group (group B) consisted of similar number of age, gender, BMI and socioeconomically matched subjects who did not use air conditioner nearly at all. Actual, predicted and percentage of predicted value of PEFR were estimated in both the study and control group using Minato Autospiro AS-507. Statistical analysis was done by unpaired Student’s ‘t’ test and p value 0.05 was taken as level of significance. In this study mean actual and percentage (%) of predicted value of PEFR were significantly lower in AC users in comparison to nonusers in case of both male and female. Between two groups of AC users, mean actual and percentage of predicted value of PEFR were significantly lower in the group where AC temperature was constantly regulated in between 18°C to 22°C in comparison to the group where AC temperature was constantly regulated in between 23°C to 25°C. Use of AC can significantly reduce lung functions of AC users and lower AC temperature is associated with more reduction of PEFR in AC users.