In order to assess the cement dust levels at the factory of the Beninese Cement Industry (BCI), at Xwlacodji, seven sampling stations (numbered 1 to 7) were set inside the industry and nine (numbered 8 to 16) were set around the factory in January, February, August and December. With the method of stainless steel plate according to NFX 43-007 AFNOR Standard, the different stations were monitored daily for dust collection all month long. The results revealed that the mean values of cement dusts inside BCI in g/m 2/day ranged from 1.608 to 8.752 in January, from 1.13068 to 6.14924 in February, from 0.9654 to 5.2502 for August and from 1.7220 to 9.3620 for December. With regard to outside BCI, the mean values of dusts rose from 8.8760 to 18.9620 in December. The lowest mean values 3.2719 and 4.4124 were respectively recorded in February and August whereas the highest values 17.7309 and 18.9620 were respectively recorded in January and December. Our study revealed month variation in cement dust deposition with the highest values in December and January and the lowest values in February and August. It was observed that the content in cement dusts recorded outside the cement industry were extremely higher than those recorded inside the cement industry. The values in the present study have far exceeded all the international safety values (1 g/m 2/day for AFNOR and 350 mg/m 2/day TA-Luft) and could pose health hazards. Therefore protective measures are suggested to mitigate the risk of occupational hazards for the cement industrial workers.
Air is the basic necessity of human life. But it is noticed that the quality of air is deteriorating continuously by constantly pollution of unplanned discharges atmospheric pollutants resulting from intense industrialization, population explosion and urbanization [
In terms of industries, Cement industry occupies a place of choice since it is one of the most basic industries involved in the development of a country as cement is the most widely used building material throughout the world. Its manufacturing has caused environmental impacts at all stages of the process including emissions of airborne pollution in the form of dust, gases, noise and vibration when operating machinery and during blasting in quarries, and damage to countryside from quarrying [
Moreover, cement factories through their pollutants can have great effect on the environment. The exhaust gases and particulate matters of the dust exhausted from cement plants degrade air quality and thus create considerable environmental pollution. The impacts of cement industry are countless and the exposure to cement pollution has been linked to a number of different health problems, starting from modest transient changes in the respiratory tract and impaired pulmonary function to mortality [
In Benin, there is an exponential increasing demand for cement for building of houses and infrastructures. This has resulted in the proliferation of cement factories in order to meet the supply. It is acknowledged that cement industry is a major source of the imbalances of the environment and producing air pollution hazards. The industry releases huge amounts of cement dusts into the atmosphere which settle on the surrounding areas and cause various adverse effects. The present study is aimed at assessing the cement dusts emitted by Xwlacodji cement industry established in the heart of Cotonou, the economical capital of Benin.
This investigation took place in the factory of the Beninese Cement Industry (BCI) at Xwlacodji. BCI is situated in the 5th district of Cotonou (Republic of Benin) between 2˚26'15" and 2˚26'30" eastern latitude and between 6˚21'0" and 6˚21'5" northern longitude. The population of Xwlacodji is about 32,864 [
The materials used included stainless steel plate of 50 mm2 for collecting cement dust, silicone oil to bind particles of dust, plastic packaging to protect cement dust samples, a wooden carrier wafer of 2 m, a screwdriver and a scale. The method used was that of stainless steel plate according to NFX 43-007 AFNOR Standard. The plates coated with hydrophobic binder were devices for collecting cement dusts in the atmosphere. The plates were set according to NFX 43-007 AFNOR Standard. The dust particles dropped on the plates by gravitation
were retained and stabilized by the coat. The plates were weighed before installation (without particles and plastic packages). Once removed, they were immediately packed in a plastic wrapper to prevent the loss of some particles. The whole was weighed and the mass of dust is obtained by subtracting from the whole the mass of the empty plate and that of the plastic package.
In terms of statistical analyses, cement dust values were expressed as mean ± SD. Test of Mann Whitney/Wilcoxon at P < 0.0001 was carried out to compare the different cement dusts recorded at the different stations inside and outside the factory. Beside student test was conducted to compare the values in this study to the international safety limits.
The content in cement dusts registered at different stations inside the cement plant is gathered in
The order of dusts accumulation on the plates at the different stations at all periods of sampling at P < 0.001 is as follows: S5 > S2 > S3 > S7 > S6 > S1 > S4 for January, February, August and S5 > S2 > S3 > S7 > S6 > S1 > S4 for December.
The mean values of cement dusts range from 1.608 to 8.752 in January, from 1.13068 to 6.14924 in February, from 0.9654 to 5.2502 for August and from 1.7220 to 9.3620 for December. Inside the cement plant the lowest and the highest mean values were always recorded at stations 4 and 5 respectively. From
The values in dusts content recorded outside of the cement industry are gathered in
S1 | S2 | S3 | S4 | S5 | S6 | S7 | |
---|---|---|---|---|---|---|---|
January (S5 > S2 > S3 > S7 > S6 > S1 > S4 at P < 0.001) | |||||||
Min | 2.168 | 3.85 | 3.822 | 0.788 | 4.292 | 3.256 | 3.7 |
Max. | 6.618 | 11.752 | 11.67 | 2.408 | 13.102 | 9.938 | 11.294 |
Mean | 4.42 | 7.85 | 7.796 | 1.608 | 8.752 | 6.638 | 7.544 |
SD | 1.24 | 2.202 | 2.186 | 0.45 | 2.454 | 1.862 | 2.116 |
February (S5 > S2 > S3 > S7 > S6 > S1 > S4 at P < 0.001) | |||||||
Min. | 2.17308 | 3.85914 | 3.83194 | 0.79112 | 4.30246 | 3.26334 | 3.70834 |
Max. | 5.30846 | 9.42722 | 9.36078 | 1.93254 | 10.5102 | 7.97176 | 9.05882 |
Mean | 3.10584 | 5.51562 | 5.47674 | 1.13068 | 6.14924 | 4.66406 | 5.30008 |
SD | 0.76158 | 1.35248 | 1.34294 | 0.27726 | 1.50784 | 1.14368 | 1.29962 |
August (S5 > S2 > S3 > S7 > S6 > S1 > S4 at P < 0.001) | |||||||
Min. | 1.8792 | 3.3373 | 3.3138 | 0.6841 | 3.7207 | 2.8221 | 3.2069 |
Max. | 4.7945 | 8.5145 | 8.4545 | 1.7454 | 9.4927 | 7.2000 | 8.1818 |
Mean | 2.6518 | 4.7092 | 4.6760 | 0.9654 | 5.2502 | 3.9822 | 4.5252 |
SD | 0.5924 | 1.0520 | 0.2157 | 1.1729 | 0.8896 | 1.0109 | 1.6016 |
December (S5 > S2 > S3 > S7 > S6 > S1 > S4 at P < 0.001 ) | |||||||
Min. | 1.2860 | 2.2820 | 2.2660 | 0.4680 | 2.5440 | 1.9300 | 2.1940 |
Max. | 13.2100 | 23.4540 | 23.2900 | 4.8100 | 26.1480 | 19.8340 | 22.5360 |
Mean | 4.7280 | 8.3960 | 8.3380 | 1.7220 | 9.3620 | 7.1000 | 8.0680 |
SD | 3.2140 | 5.7100 | 5.6680 | 1.1700 | 7.1000 | 4.8280 | 5.4860 |
S8 | S9 | S10 | S11 | S12 | S13 | S14 | S15 | S16 | |
---|---|---|---|---|---|---|---|---|---|
January (S14 > S10 > S9 > S16 > S12 > S15 > S8 > S13 > S11 at P < 0.001) | |||||||||
Min | 4.66246 | 7.696 | 8.38666 | 4.07 | 5.67334 | 4.588 | 8.695 | 5.95902 | 6.43078 |
Max. | 14.23202 | 23.49176 | 25.6 | 12.42352 | 17.31764 | 14.0047 | 26.54118 | 18.35004 | 19.62976 |
Mean | 9.50772 | 15.693738 | 17.10214 | 8.29956 | 11.5691 | 9.35588 | 17.7309 | 10.66112 | 13.1137 |
SD | 2.66672 | 4.401752 | 4.79678 | 2.32784 | 3.24488 | 2.62412 | 4.97314 | 0.8932 | 3.67812 |
February (S14 > S8 > S16 > S12 > S10 > S15 > S11 > S13 > S9 at P < 0.001) | |||||||||
Min. | 6.3418 | 2.2892 | 4.1780 | 2.9017 | 4.4500 | 2.3733 | 8.8629 | 3.2226 | 5.1792 |
Max. | 15.4921 | 5.5923 | 10.2062 | 7.0885 | 10.8706 | 5.7976 | 21.6506 | 7.8723 | 12.6520 |
Mean | 9.0640 | 3.2719 | 5.9714 | 4.1473 | 6.3601 | 3.3920 | 12.6672 | 4.6059 | 7.4023 |
SD | 2.2225 | 0.8023 | 1.4642 | 1.0169 | 1.5596 | 0.8318 | 3.1061 | 1.1294 | 1.8151 |
August (S14 > S10 > S9 > S16 > S12 > S15 > S8 > S13 > S11 at P < 0.001) | |||||||||
Min. | 4.0411 | 6.6703 | 7.2690 | 3.5276 | 4.9172 | 3.9766 | 7.5362 | 2.3888 | 5.5737 |
Max. | 10.3101 | 17.0182 | 18.5454 | 9.0000 | 12.5455 | 10.1454 | 19.2273 | 14.2204 | 14.2204 |
Mean | 5.7023 | 9.4124 | 10.2571 | 4.9777 | 6.9387 | 5.6113 | 10.6342 | 6.8862 | 7.8650 |
SD | 1.2739 | 2.1027 | 2.2914 | 1.1120 | 1.9972 | 1.2535 | 2.3757 | 2.8861 | 1.7570 |
December (S14 > S10 > S9 > S16 > S12 > S15 > S8 > S13 > S11 at P < 0.001 ) | |||||||||
Min. | 2.7640 | 4.5620 | 4.9720 | 2.4120 | 3.3640 | 2.7200 | 5.1540 | 2.8320 | 3.5980 |
Max. | 28.4020 | 46.8780 | 51.0840 | 24.7900 | 34.5560 | 27.9460 | 52.9660 | 29.0980 | 36.9660 |
Mean | 10.1680 | 16.7840 | 18.2900 | 8.8760 | 12.3720 | 10.0060 | 18.9620 | 10.4180 | 13.2340 |
SD | 6.9140 | 11.4100 | 12.4340 | 6.0340 | 8.4120 | 6.8020 | 12.8920 | 7.0820 | 8.9980 |
The patterns of adsorption of dust particles on the plates are S14 > S10 > S9 > S16 > S12 > S15 > S8 > S13 > S11, S14 > S8 > S16 > S12 > S10 > S15 > S11 > S13 > S9, S14 > S10 > S9 > S16 > S12 > S15 > S8 > S13 > S11, S14 > S10 > S9 > S16 > S12 > S15 > S8 > S13 > S11 respectively for January, February, August and December at P < 0.001).
In December, the mean values of dusts rose from 8.8760 (station 11) to 18.9620 (station 14). The lowest mean values 3.2719 (Station 9) and 4.4124 (Station 9) were respectively recorded in February and August whereas the highest values 17.7309 (Station 14) and 18.9620 (Station 14) were respectively recorded in January and December. Although the patterns of dusts accumulation on the plates are not the same, station 14 remained the dustiest station at all periods whereas station 11 recorded the lowest values in January, August and December.
Moreover, the dust mean values recorded in December and January were much higher than those recorded in February and August leading to the inference that December and January were the dustiest months whereas February and August are the least dusty months inside as well as outside the cement factory.
Comparison of the dust mean values from BCI with international values revealed that the present values are much higher than those reported by Toulouse annual report, ORAMIP and Henni-Chebra et al. [
The present study suggested that the highest mean values were recorded at packing station in contrast to station at administration level which recorded the lowest mean values. Similar observations were reported by Kakooei et al. [
Our study revealed month variation in cement dust deposition with the highest values in December and January and the lowest values in February and August. This report is in accordance with the results of Mehraj et al. [
The comparison of the values of cement dusts recorded inside the cement plant with those recorded outside and the international safety values (AFNOR = 1 g/m2/day and TA-Luft = 350 mg/m2/day) is plotted on
From
Besides, it is also noted that all the international safety values (1 g/m2/day for AFNOR and 350 mg/m2/day TA-Luft) are far exceeded.
The levels of cement dusts and the frequencies and amplitudes of exceeding the permissible limits have far- reaching implications directly or indirectly to man.
In fact, numerous epidemiological studies associated a variety of pathologies with cement dust exposure. Several studies have demonstrated linkages between cement dust exposure, chronic impairment of lung function and respiratory symptoms in human population. [
Also, cement dust has been identified as an eye allergen and can cause runny eyes, and Conjunctivitis [
Additionally, Dolgner et al. [
Besides, there is an association between cement dust and genetic damages. Fatima et al. [
mutagenic effects of occupational exposure to cement dust such as chromosomal damage, chromosomal aberrations in workers.
Moreover, cement dust could cause heat impairment. Actually, Maciejewska [
The present study reveals high level of cement dust at all stations inside and outside the Beninese Cement Industry exceeding all the international permissive values. It poses public and occupational health hazards. Therefore, workers and health officials should work together to adopt preventive measures, such as well-ventilated work areas, use of appropriate uniform, mask, safety goggles for effective protection. It is also suggested that workers must undergo periodic medical surveillance tests. These measures would help to mitigate the risk of occupational hazards for the cement industrial workers.
TheodoreSoussia,PatientGuedenon,RafiouLawani,Claudia DoutetienGbaguidi,Patrick A.Edorh, (2015) Assessment of Cement Dust Deposit in a Cement Factory in Cotonou (Benin). Journal of Environmental Protection,06,675-682. doi: 10.4236/jep.2015.67061