Dose-effect relationship on annoyance and sleep disturbance due to industrial and aircraft noise in Calabar, Cross River State, South-South Nigeria.

Abstract

Dose-effect relationship on annoyance and sleep disturbances due to industrial and aircraft noise in Calabar, Cross River State, South-South Nigeria has been investigated.  The objectives of the work was to find a quantitative dose-response relationship on annoyance and sleep disturbance for persons exposed to industrial and aircraft noise in the study area Calabar, Cross river State, South-South Nigeria, these effects of the noise  from these two sources on people have also been compared. Noise levels from industrial machines ranged between 101-131 dB(A) while that of aircraft was 95 -127 dB(A) as it affected the workers and residents around the neighborhood. It has also been established from the findings that with increase in day-night sound levels from these noise sources, the level of annoyance of the people also increased.  On comparison, aircraft noise increased annoyance on the people than industrial noise.  This trend was not different when comparing the effects of noise from these two noise sources on sleep of the people.  It is believed that the high level of aircraft noise from aircraft when landing and taking off and the sudden and intermittent nature of the noise as compared to the steady noise levels of industrial machines are contributory factors. Speech intelligibility of the pupils in Federal Airport Authority of Nigeria (FAAN) nursery primary/secondary school and that of the students of the Federal Government Girls College, Calabar is likely to be greatly affected by this high level of noise as rated by the respondents. Workers in the industries and airport are also bound to surfer other effect such as hearing loss, conversation disturbance, headache and fatigue. Respondents in the noise exposed group were more sharply annoyed by aircraft and industrial noise than the non exposed group.  Sleep disturbance is deemed undesirable and may be considered an impact caused by noise exposure.  Subjective reactions to noise vary greatly from person to person and from time to time and sleep disturbance and annoyance is no exception.

Keywords:  Dose-Effect, Annoyance, Sleep disturbance, Industrial noise, Aircraft noise, Day-night sound levels.