Markets in developing countries serve as vital socioeconomic institutions. Their level of activities often reflects the prosperity of the country. Ibadan is now regarded as the second largest city in Black Africa next only to Lagos Metropolis. Much of the commercial activities in the city take place in the traditional markets within residential premises. The number of markets in the city have grown from 26 in 1972, 36 in 1985 and to about 47 by 1994. While these are well established, there are numerous other sites where selling and buying take place as the 'Yoruba' ethnic group, which is predominant in the city, are shrewd traders by tradition. The types of market stalls vary in Ibadan and they include: covered and lockable stalls, open stalls, open trading units with tables, and sale 'counters'.
The number of market stalls range from less than 100 (at Ijokodo area), to well over 5000 stalls at Dugbe and Gbagi areas Vagale , Filani & Iyun . The quality of physical environment in the city markets is generally deplorable with the exception of a few newly built markets. Amenities such as water supply, toilet facilities and waste disposal are poor but access by road is reasonably adequate. Most of the major roads are open to them thereby exposing them to noise and vehicular emissions. Markets in the indigenous or traditional areas are always crowded and going by foot is more convenient.
In recent years it is being realized that noise does not have to be loud to cause health problems. There is increasing evidence that exposure to relatively low levels of noise for long periods can affect health, raising blood pressure, disrupting cognitive development in children, disturbing sleep and prompting psychiatric disorders Anon . The data on noise levels in Nigerian urban centers is very limited and no information is available among the markets in particular, which are wide spread among the residential areas all over the city. This paper describes noise levels in various markets areas in Ibadan city, identification of locations where the noise levels are above the permissible limits, and the activities that contribute to such higher levels.
There are about 47 major markets in Ibadan city. These markets are of five types depending on the time of operation:
a. Morning markets-held between 5.00AM and 12Noon and sell perishable goods such as vegetables and fruits.
b. Day markets most common in Yoruba tradition and operate between 8AM and 7PM; characterized by very intensive commercial activities with high density of population, congestion and noise.
c. Night markets - operate between 5PM and 10.00PM and specialize in selling various cooked foods; urbanization, however, has drastically reduced these types.
d. Day and Night markets function between 8.00AM and 10.00PM and they deal with a variety of commodities.
e. Periodic markets - held at intervals of 5 to 17 days during daytime; people from various nearby towns come and exhibit indigenous goods for sale.
Out of these, 22 were selected by random sampling. Night markets were not included in the study as they mostly deal with food items. Every market was visited during the peak period between 10 AM and 2 PM on working days. The sound levels were measured using CEL-269 Digital Integrating Sound Level Meter made in UK by CEL Instruments. At every point several readings, generally not less than three were taken and mean values and standard deviations were calculated before presenting in Tables.
The noise levels in various markets are presented in Table 1. The results indicate that the lowest mean noise level was 58.7dB in Railway yard and New Gbagi markets. The highest levels of 100dB at slaughter slab area of cow section in Bodija market 88.13dB were recorded in plank section of Bodija market, which and electronic section of Agbeni market. These two markets are
is the largest in the city. However, the ranges recorded 47dB highly crowded at all times. The noise was mostly due to chatting as the lowest at the Cocoa House complex and a maximum of and loud music.
The identified areas where the noise levels are more than the permissible limits are given in Table 2. The slaughtering area in Bodija market has the highest level followed by the electronics selling areas in Agbeni. In Bodija, about 300 cows are manually slaughtered every day from early hours of morning till late in the afternoon. Here, manual labour is used in bringing the cows to the place and in the slaughtering process. The sale of electronics and musicals are generally on the roadside and to attract the passersby, the traders play loud music. Other areas where the noise levels are above the permissible limits were woodcutting, block making, grinding, petrol generators, and vulcanizing areas. The activities that contribute to higher noise levels are given in Table 3. Loading, unloading, grinding, cutting, sawing, tailoring, and cement block making are some of the activities that contribute to higher noise levels. Noise levels at the access roads and the road junctions are given in Table 4. The minimum recorded was 53dB and the maximum was 86dB. Some markets particularly .