The application of biomaterials in ecological remediation of land pollution: bioremediation of heavy metals in cement contaminated soil using white-rot fungus Pleurotus sajor-caju

Received: 06-Mar-2023, Manuscript No. PULJECT-23-6218; Editor assigned: 09-Mar-2023, Pre QC No. PULJECT-23-6218 (PQ); Reviewed: 24-Mar-2023 QC No. PULJECT-23-6218; Revised: 08-May-2023, Manuscript No. PULJECT-23-6218 (R); Published: 16-May-2023, DOI: 10.37532/PULJECT.2023.7(1).1-6.

Citation: Olalekan RM, Bukola RW, Omowunmi FO. The application of biomaterials in ecological remediation of land pollution: bioremediation of heavy metals in cement contaminated soil using white-rot fungus Pleurotus sajor-caju. J Environ Chem Toxicol 2023;7(1):1-6.

This open-access article is distributed under the terms of the Creative Commons Attribution Non-Commercial License (CC BY-NC) (http://creativecommons.org/licenses/by-nc/4.0/), which permits reuse, distribution and reproduction of the article, provided that the original work is properly cited and the reuse is restricted to noncommercial purposes. For commercial reuse, contact reprints@pulsus.com

Abstract

Environmental pollution is a result of cement manufacture. Soil and plant analysis at the Lafarge Cement Factory (LCF) as well as bioremediation of soils contaminated with cement at various concentrations were done. Human induced heavy metal mobilization in the biosphere has developed into a significant phenomenon. This study used atomic absorption spectrophotometry to determine the levels of Ni, Cr, Pb, and Zn in 15 soil samples and 36 Synedrella nodiflora plants that were taken from the area around the lafarge cement factory in Sagamu, Nigeria (AAS). The findings of the metal study showed that some metals exceeded the essential limitations for the soil and plants, as well as the natural background levels.

The white rot fungus Pleurotus sajor-caju was investigated for its ability to mineralize heavy metals. Five kilograms of soil was carefully weighed and thoroughly mixed with cement to give 0.1%, 0.2%, 0.3% and 0.4% contamination levels, five kilograms of the contaminated soil from the vicinity of the cement factory with an unknown percentage level of contamination was also weighed and a set control was also weighed (0%). Following the addition of the fungus to the soil samples using rice straw as a substrate, the samples were incubated for a month. After a month of the fungus' incubation, the soil's heavy metal level significantly decreased. After a month, P. sajor-caju was able to mineralize the heavy metals and improve the soil's nutrients. In order to initiate the ecological restoration process for soil contaminated by cement, P. sajor-caju can be used as a bioremediation agent.

Keywords

Bioremediation; Cement contamination; Pleurotus sajor-caju; Heavy metals; Ecological restoration; Land pollution; Ogun state; Nigeria

Introduction

The primary component of cement, Cement Kiln Dust (CKD), is a fine, gray or white powder that is typically kept as trash in open pits and landfills. The primary component of concrete used to build modern structures is cement. Cement manufacture, however, produces a lot of cement dust. Short term contact to cement dust may not be problematic, but ongoing exposure to the substance can harm plants and animals irreparably [1]. Air pollution has a great impact on human health, climate change, agriculture and natural ecosystem. Besides health, cement factories are deteriorating environment as shown by series of studies [2]. Atmospheric emissions from industrial establishments are one of the major sources of environmental pollution. One type of industry that causes particle pollution is the cement industry [3]. The main inputs of cement activity on the environment are the broadcasts of dust and gases [4]. Cement dust spreads along large areas through wind, rain etc. and are accumulated in and on soils [5]. Bioremediation is a biotechnological approach of rehabilitating areas degraded by pollutants or otherwise damaged through mismanagement of the ecosystem using plants and microorganisms to remove or detoxify environmental contaminants [6]. For bioremediation to be effective, microorganisms must enzymatically attack the pollutants and convert them to harmless products. In this work, we will focus on the agricultural impact of cement as one of the major soil contaminants in one of the major cities in Nigeria and how its effects can be corrected through the process of bioremediation. This study was conducted to determine the amount of heavy metals deposition by cement dusts on soil and Synedrella nodiflora plants. The study also looked into the bioremediation potential of Pleurotus sajor-caju on heavy metal content of cement contaminated soil. Thus, while soil pollution is caused by the presence of man-made chemicals or other toxic material in the natural soil environment. The most common soil pollutants are petroleum hydrocarbons, solvents, pesticides, lead and other heavy metals [7]. The occurrence of toxic material in most areas correlates directly with the degree of industrialization and intensity of chemical usage in those areas. Cement is made up of four main compounds: Tricalcium Silicate (3CaO.SiO₂), Dicalcium Silicate (2CaO.SiO₂), Tricalcium Aluminate (3CaO.Al₂O₃), and a Tetra-calcium Aluminoferrite (4CaO.Al₂O₃Fe₂O₃). Small amounts of uncombined lime and magnesia also are present, along with alkalis and minor amounts of other elements.

Cement dust of sufficient quantities have been reported to dissolve leaf tissues. Other reported effects of cement dust on plants include reduced growth, reduced chlorophyll, clogged stomata in leaves, cell metabolism disruption, interrupt absorption of light and diffusion of gases, lowering starch formation, reducing fruit setting, inducing premature leaf fall and leading to stunted growth thus causing suppression in plants and in animals it leads to various respiratory and hematological disease, cancers, eye defects and genetic problems. Besides gaseous and particulate pollutants there are also enhanced levels of toxic heavy metals in the environment of cement factory likely cobalt, lead, chromium, nickel, mercury posing potential hazard for all living organisms. Increased concentrations of the above pollutants cause progressive reduction in the photosynthetic ability of leaves, mainly a reduction in growth and productivity of plants. Metal toxicity in plants has been reported by various authors [8]. Among the heavy metals, mercury, lead, nickel, chromium are most dangerous heavy metals released by cement factories and is responsible for causing various biochemical changes which also includes cytotoxic and mutagenic effects such as chromosomal aberrations, stickiness, c-mitosis, chromosomal bridge, chromosome fragmentation, vagrant chromosomes, DNA fragmentation etc. in various plants. Bioremediation has been intensively studied over the past two decades, driven by the need for a low cost, in-situ alternative to less expensive engineering based remediation technologies. Bioremediation has been applied to remove crude oil motor oil and diesel fuel from soil but the removal efficiency is highly variable. Plants can indirectly influence degradation by altering the physical and chemical conditions of the soil [9].

While, bioremediation remain a non-invasive technique that leaves the ecosystem intact. It can deal with lower concentration of contaminants where the cleanup by physical or chemical methods would not be feasible but can only be effective where environmental conditions permit microbial growth and activity, its application often involves the manipulation of environmental parameters to allow microbial growth and degradation to proceed at a faster rate. The factors that must be optimized for successful bioremediation are: Bio stimulation, oxygen and inorganic nutrients, pH, temperature, water availability, and adsorption effects. Pleurotus sajor-caju fungi have been well known for metal removalability from aqueous phase [10]. The multi laminate and micro fibrillar structure of fungal cell wall along with distinctive aspects of high percentage of cell wall material attributes excellent metal binding properties. P. sajor-caju is recognized as a mushroom with distinct properties. It can be cultivated within a wide range of temperatures on different natural resources and agricultural wastes. The sporophores of P. sajor-caju have 26.9% protein having high digestibility values and all essential seventeen amino acids in good concentration found that P. sajor-caju and Pleurotus fabellatus, when compared with other basidiomycetes of the genus Pleurotus sp., are collectors of heavy metals and also have high rates of degradation of the medium where they are growing. The mycelium of fungi can absorb heavy metals, which can accumulate and move to the other parts of the fungal body in concentrations, and are sometimes far higher than that of the medium. Its high metal absorbing property makes P. sajor-caju ideal for bioremediation purposes [11].

Materials and Methods

Description of the sample site

Lafarge cement factory is located in the southern part of Sagamu a small town in the Southwestern part of Nigeria, it lies between latitude 6° 50' North and longitude 4° 00' East. The area is characterized by high annual temperature, high rainfall, and high relative humidity and it is classified as humid tropical region, the soil type is ferralitic. The surrounding vegetation consists of trees, shrubs and herbs [12]. The experiment for this study was carried out in the department of crop protection and environmental biology, university of Ibadan and at national horticultural research institute Ibadan.

Collection of samples

The soil sample used for this experiment was collected at various distances from the West African Portland cement company Lafarge, facility, Sagamu, Ogun state, Nigeria. In May, 2014, twelve soil samples and 36 plant samples of (Synedrella nodiflora) were collected from designated sampling points [13]. Soil samples were collected from the top soil at not more than 15 cm depth and were scrapped into labeled polyethylene bags. The soil used for control was gotten from the crop garden at the department of crop protection and environmental biology, university of Ibadan. Spawns of P. sajor-caju were obtained from the mushroom unit of the National Horticultural Research Institute (NIHORT), Jericho Ibadan, and Oyo state, Nigeria.

Sterilization of glasswares and treatment of soil samples

Glasswares were washed thoroughly with a solution of detergents and rinsed with clean water before allowed to dry. Sterilization of glasswares was done for 150 mins at 60℃. Soil samples meant for degradation studies was sterilized using an autoclave at 121℃ for 15 mins after which they are allowed to cool to room temperature [14].

Experiment 1: To evaluate the quantity of heavy metals as a result of cement dust deposition in the soil and the flora around the Sagamu cement factory and a nearby farm. In the laboratory, the collected soil and plant samples were air dried for 2 weeks at room temperature for 27℃, the soil samples were sieved using a 2 mm mesh sized sieve to obtain a homogenous distribution of soil contents.

Preparations for heavy metals in soils: One gramme of the sieved soil was accurately weighed and transferred to a 100 ml beaker, 20 ml of 1:1 of nitric acid (analar grade) was added to the weighed sample, the sample was then boiled gently on a hotplate until the volume of nitric acid was reduced to 5 ml. 20 ml of distilled water was added to the sample and boiled gently again until the volume was 10 ml, which was then allowed to cool. The suspension was filtered through a whattman filter paper [15]. Washing the filter paper and the beaker with small portions of distilled water, a volume of 25 ml was obtained, this was then made up to 50 ml using a 50 ml graduated flask. The samples were analysed for heavy metals using the atomic absorption spectrophotometer.

Preparations for heavy metals in plants: The root and shoot of Telfaria occidentalis and Synedrella nodiflora were air dried for 2 weeks at room temperature of 27℃ and the plant parts were ground and ashed in a muffle furnace at a temperature of 500℃-550℃. Heavy metals were extracted using the double acid extraction method [16].

Soil pH analysis: The soil pH was determined by weighing 10 g of air dried soil samples into beakers, 10 ml of distilled was then added, after which the mixture was stirred manually for 5 mins with a glass rod and it was allowed to stand for 30 mins [17]. The pH was then read using the pH meter.

Preparation of contamination

5 kg of homogenized soil sample was carefully weighed and poured in a clean basin. No cement was added. This served as the control with a contamination level of 0% and was labeled as A. Four separate samples of 5 kg of homogenized soil were carefully weighed and poured into separate clean basins. Cement was then added to each sample in quantities of 5 g, 10 g, 15 g and 20 g and mixed thoroughly [18]. This gave a contamination concentration level of 0.1%, 0.2%, 0.3% and 0.4% and each was labeled B, C, D and E respectively with increasing concentration. 5 kg of the naturally contaminated soil was carefully weighed and no cement was added and was labeled F.

Experiment 2: To investigate the effect of P. sajor-caju incubation on the heavy metal content of cement contaminated soil. The procedures were according to the method of and modified as follows: 200 g of each sample was weighed into transparent polyethylene bags, replicated four times and labeled. 5 g of rice straw was added after which 10 g of vigorously growing spawns of the fungi was added. Plastic necks were used to support the nylons so that they could be corked with cotton wool and the necks wrapped in foil. The nylons were also doubled to prevent tearing or melting due to heat. They were placed in Complete Randomized Design (CRD). Making a total of another 24 samples. At four weeks after inoculation, mycelia-ramified waste was separated from the spawns and rice straws and the soil was analysed for physicochemical properties and heavy metal content after air-drying [19].

Data and statistical analysis

Standard error values were calculated and data was analysed using a one way Analysis of Variance (ANOVA). Fishers Least Significant Difference (LSD) was used to identify where there was significant differences between the treatment means at 95% confidence interval (P<0.05).

Results and Discussion

Nutrient composition of contaminated soils around LCF Sagamu, Ogun state

Table 1 shows the nutrient levels of soils contaminated with cement deposit as a result of the factory activities. An increase in soil pH was observed at a distance closer to the cement factory and the pH decreased as the distance increased. The lowest pH was observed at a distance of 100 m where a farm is located, followed by the control and then at 60 m, 40 m and 20 m respectively. There was no significant difference in the Organic Matter (OM) content of all the soils at the various distances that was tested for including the control. The soils that were used for control was observed to have the highest phosphorus content, this is followed by the phosphorus content in the soils at 60 m distance away from the factory, while there was no significant difference in the phosphorus content in the soils at 20 m, 40 m and 100 m. There was a relatively significant difference in the calcium content of the soil at 20 m and the soil at 100 m. This is showing a decrease in the calcium content of the soils at 100 m distance away from the factory [20]. The increase in the high content of calcium in the soil used for control cannot be compared with the calcium content in the other soils at the varying distances, this is because, the soil used for control was gotten from a non-cement producing area. There was no significant difference in the sodium content of all the soils that were sampled at the various distances but the least quantity was observed at 100 m, this was also applicable for potassium.

Table 1: Nutrient composition of soils around LCF Sagamu, Ogun state.

Distribution of heavy metals in soils around LCF, Sagamu, Ogun state

Table 2 shows the distribution of heavy metals in soils around Lafarge cement factory, Sagamu, Ogun state. For the soil samples, the highest level of heavy metal content corresponded to zinc, at a distance of 60 m followed by lead. The lowest levels of heavy metal were recorded for chromium and nickel. A significant decrease in the quantity of zinc was observed at 100 m away from the Lafarge cement factory. According to the present study, the range for nickel was 2.50-25.21 mg/kg. The elemental concentrations in the soil samples are in the decreasing order of Zn>Pb>Cr>Ni.

Table 2: Distribution of heavy metals in soils around LCF, Sagamu, Ogun state.

Heavy metal content of uncontaminated soil and cement-contaminated soils

Table 3 shows the heavy metal content of uncontaminated soil and different concentrations of cement contaminated soils before incubation with Pleurotus sajor-caju (zero month). A general increase was observed as the concentration levels increases for lead, chromium, and zinc, this increase was significant in all the treatments. Significant differences were also observed for copper and nickel at 0% and 0.1%.

Table 3: Heavy metal content of uncontaminated soil and cement contaminated soils incubated with Pleurotus sajor-caju at zero months.

Table 4 shows the heavy metal content of uncontaminated soil and different concentrations of cement contaminated soils at one month after incubation with Pleurotus sajor-caju. The result shows that lead at the concentration of 0.4% had the highest mean of 31.60 mg/kg and the lowest mean of 6.70 mg/kg at 0% concentration. The 0.4% concentration of lead was however significantly different from all other concentration levels at P<0.05. This trend was also observed with chromium which had the highest mean of 20.18 mg/kg at 0.4% level of concentration and the lowest mean of 1.94 mg/kg at 0% concentration. This was significantly different from other concentrations of 0.1%, 0.2%, and 0.3% at P<0.05. The highest reduction for zinc was observed at the contaminated soil obtained from a farm at the site of the Lafarge cement factory with a mean of 12.10 mg/kg which was significantly different from all the other treatment used except at 0.1% level of concentration. Nickel had the highest reduction at 0.1% concentration with a mean of 37.7 mg/kg and this was significantly different from all the other treatments. Copper had the highest reduction of 12.40 mg/kg at 0.4% concentration; this was not significantly different to 0.1% concentration but was significantly different to the other treatments.

Table 4: Heavy metal content of uncontaminated soil and cement contaminated soils incubated with Pleurotus sajor-caju at one month.

Studies on soil have implicated these metals as reaching or exceeding toxicity levels. For example, Bennet, et al. has shown that the toxic level of chromium in soil is around 2-50 mg/kg and this in comparison with chromium measurement in the current situation which is high. The critical level for nickel in soil have been investigated by many researchers and estimated to be in the range of 2-50 mg/kg. According to the present study, the range for nickel (2.50-25.21 mg/kg) is alarming suggesting that nickel pollution is critical in the investigated area. The study indicated high bioavailability of zinc in the cement-contaminated soil used in the experiment. This high bioavailability of Zn may be due to the high soil pH, which can increase solubility. The organic matter content of soil can favour bioavailability of Zn, making it more abundant for uptake by vegetables, as metals associated with organic matter have high mobility due to decomposition and oxidation of organic matter with time. There have been reports that high pH increases solubility of copper in soil, making it phytobioavailable. The presence of high concentrations of heavy metals (zinc, chromium, nickel and lead) in the soil of the study area indicates that it has been affected by anthropogenic activity, in particular the cement factory. The high levels of heavy metals in these soils have increased the accumulation of metals in the flora around the cement factory. As a result of the complicated relationship in levels of individual element in the different set of samples, focusing on their distribution in terms of distance and direction will be futile, instead we find a way of discussing contamination status of the sampling sites. Surface soil and vegetation are considered as major sink of airborne metals. Consequently, the measurement of metals in these media can be useful to establish trends and abundance and their consequences as a result of natural changes and those caused by man. Of the two environmental matrices, the soil has largely been used to establish metal contamination in relation to natural or anthropogenic influence on the environment. Having established a good correlation between the soil and vegetation samples under the current investigation, the use of the soil data in explaining sources of environmental contamination will provide good judgment in understanding contamination of heavy metals by atmospheric deposition and industrial activities. This study showed that the mycelia elongation increased progressively up to 12 DAI. However, 0.1% contamination level had the highest vertical elongation level closely followed by 0.2% contamination level with 0.4% contamination level and the contaminated soil from cement factory having the lowest vertical elongation. This ability of the white rot fungus to grow on all the concentration levels agrees with the fact that white rot fungi grow by hyphal extension and thus can reach pollutants in the soil in ways that other organisms cannot. The results obtained from this study showed an increase in the nutrient content of the soil with the increase of the incubation period. Increase in percentage organic carbon and organic matter in soil incubated with Pleurotus sajor-caju was also observed with the increase of the incubation period, thus indicating that degradation must have taken place. This is similar to the work done by Raimi and Sabinus; Adenipekun, and Omoruyi, in bioremediation of cement and battery polluted soil using Pleurotus pulmonarius, where higher organic carbon and organic matter were recorded compared to control samples resulting in remediation of the samples. An increase in potassium and decrease in phosphorus occurred in both the cement-free and the cement-contaminated soil from 400.0 mg/kg to 900.0 mg/kg, 42.25 mg/kg to 17.51 mg/kg for the cement-free soil, and from 170.7 mg/kg to 200.0 mg/kg, 35.55 mg/kg to 17.20 mg/kg for the cementcontaminated soil. This indicates that a degradation has occurred. The reduction in calcium observed in both soil samples showed that P. sajor-caju accumulated the calcium from both soil samples. The reduction is higher in the cement contaminated soil due to the fact that cement is rich in calcium.

Until the current investigation, data on metal levels in the two environmental matrices (soil and vegetation) from the area under the potential influence of the emissions of these pollutants by the cement facility here evaluated were scarce. Therefore, the current results should be of a special interest as reference values in future evaluations of the facility, which was deemed very necessary. From the results of the current investigation, it recommend that future cement production facilities must be set away from settlements and farms, and that our environmental regulations must be strengthened so as to prompt current industrial operators to take precautions and new techniques to protect the environment from hazardous pollutants. The reason being that the human body is of a complex structure, therefore, the accumulation of metals can cause many toxic effects, which can influence different mechanisms on the body.

By way of monitoring the operational influence of the cement facility on the environment, this study underlines the need for replicating periodic studies (two years duration) on the facility on the environment in addition to the evaluation of the facility on human health and more research should also be done on the health implication of vegetables grown in the area on man. Contaminated lands generally result from past industrial activities when awareness of the health and environmental effects connected with the production, use, and disposal of hazardous substances were less well recognized than today. The problem is worldwide, and the estimated number of contaminated sites is significant. It is now widely recognized that contaminated land is a potential threat to human health, and its continual discovery over recent years has led to international efforts to remedy many of these sites, either as a response to the risk of adverse health or environmental effects caused by contamination or to enable the site to be redeveloped for use. Bioremediation is an option that offers the possibility to destroy or render harmless various contaminants using natural biological activity. As such, it uses relatively low-cost, low-technology techniques, which generally have a high public acceptance and can often be carried out on site. Studies were conducted on removal of Pb, Zn, Cu and Mn from artificially contaminated soil using Pleurotus sajor-caju. The level of heavy metals in the soil reduced drastically after cultivating Pleurotus sajor-caju for a period of 30 days to bioabsorb the metals. More than 50% of the metals were removed. P. sajor-caju has thus proven its ability to enhance the nutrient content of polluted soils, and can be used as a remediator of heavy metal polluted environment.

Conclusion

In conclusion, the reduction in the pH of the soil after the inoculation of P. sajor-caju from 6.90 to 6.50 after 4 weeks for the cement-contaminated soil showed that microbial activities actually occurred in the soil. This is similar to the findings of other studies where they observed a decrease from 7.55 to 7.11 for cement polluted soil, and from 5.90 to 5.62 after 2 months of incubation. This study also showed the reduction in the heavy metal content of the different cement-contaminated soil treatments, which indicates that P. sajor-caju has accumulated the heavy metals present in the soil after incubation for four weeks. Studies were conducted on removal of Pb, Zn, Cu and Mn from artificially contaminated soil using Pleurotus sajorcaju. The level of heavy metals in the soil reduced drastically after cultivating Pleurotus sajor-caju for a period of 30 days to bioabsorb the metals. More than 50% of the metals were removed. P. sajor-caju has thus proven its ability to enhance the nutrient content of polluted soils, and can be used as a remediator of heavy metal polluted environment.

Acknowledgement

The authors are thankful to the department of crop protection and environmental biology, university of Ibadan for the encouragement of research activity and for providing necessary laboratory facilities.

Grant Support Details

The present research did not receive any financial support.

Conflict of Interest

The authors declare that there is not any conflict of interests regarding the publication of this manuscript. In addition, the ethical issues, including plagiarism, informed consent, misconduct, data fabrication and/or falsification, double publication and/or submission, and redundancy has been completely observed by the authors.

Life Science Reporting

No life science threat was practiced in this research.

References

1. Clinton-Ezekwe IC, Osu IC, Ezekwe IC, et al. Slow death from pollution: Potential health hazards from air quality in the mgbede oil fields of south-south Nigeria. Open Access J Sci. 2022;5(1):61-9.

   [Google Scholar]

2. Adak MD, Adak S, Purohit KM. Ambient air quality and health hazards near mini cement plants. Pollut Res. 2007;26(3):361.
3. Raimi M, Samson TK, Sunday AB, et al. Air of uncertainty from pollution profiteers: Status of ambient air quality of sawmill industry in Ilorin metropolis, Kwara state, Nigeria. Res J Ecol Environ Sci. 2021;1(1):17–8.

   [Google Scholar]

4. Raimi MO, Adio Z, Emmanuel OO, et al. Impact of Sawmill industry on ambient air quality: A case study of Ilorin Metropolis, Kwara state, Nigeria. Energy Earth Sci. 2020;3(1):1-25.

   [Crossref] [Google Scholar]

5. Olalekan RM, Timothy AA, Enabulele Chris E, et al. Assessment of air quality indices and its health impacts in Ilorin metropolis, Kwara state, Nigeria. Sci Park J Scient Res Impact. 2018;4(4):060-74.

   [Google Scholar]

6. Suleiman RM, Raimi MO, Sawyerr OH. A deep dive into the review of National Environmental Standards and Regulations Enforcement Agency (NESREA) Act. Int Res J Appl Sci. 2019;5:2663-77. [Crossref]

   [Google Scholar]

7. Raimi MO, Odubo TV, Omidiji AO. Creating the healthiest nation: Climate change and environmental health impacts in Nigeria: A narrative review. Scholink Sustain Enviro. 2021;6(1):1-62.
8. Raimi MO, Abiola I, Alima O, et al. Exploring how human activities disturb the balance of biogeochemical cycles: Evidence from the carbon, nitrogen and hydrologic cycles. Nitrogen Hydrologic Cycl. 2021; 2(3):23-44.

   [Crossref] [Google Scholar]

9. Olalekan RM, Omidiji AO, Williams EA, et al. The roles of all tiers of government and development partners in environmental conservation of natural resource: A case study in Nigeria. MOJ Ecol Environ Sci. 2019;4(3):114-21.

   [Google Scholar]

10. Mohammed AK, Sambo AB. Haematological assessment of the Nile tilapia Oreochromis niloticus exposed to sublethal concentrations of portland cement powder in solution. Int J Zool Res. 2010;6(4):340-44.

    [Google Scholar]

11. Iqbal MZ, Shafiq M. Periodical effect of cement dust pollution on the growth of some plant species. Turk J Botany. 2001;25(1):19-24.

    [Google Scholar]

12. Darley EF. Studies on the effect of cement-kiln dust on vegetation. J Air Pollut Control Assoc. 1966;16(3):145-50.

    [Crossref] [Google Scholar] [PubMed]

13. Raimi MO, Ezugwu SC. Influence of organic amendment on microbial activities and growth of pepper cultured on crude oil contaminated Niger delta soil. Int J Econ Energy Environ. 2017;2(4):56-76.

    [Google Scholar]

14. Sawyerr HO, Raimi MO, Adeolu AT, et al. Measures of harm from heavy metal pollution in battery technician within Ilorin metropolis, Kwara state, Nigeria. Commun Soc Media. 2019;2(2):2576-88.

    [Google Scholar]

15. Olalekan MR, Albert O, Iyingiala AA, et al. An environmental/scientific report into the crude oil spillage incidence in Tein community, Biseni, Bayelsa state Nigeria. J Environ Chem Toxicol. 2022;6(4):1-6.

    [Google Scholar]

16. Raimi OM, Sawyerr OH, Ezekwe CI, et al. Many oil wells, one evil: Comprehensive assessment of toxic metals concentration, seasonal variation and human health risk in drinking water quality in areas surrounding crude oil exploration facilities in rivers state, Nigeria. Int J Hydr. 2022;6(1): 23-2.

    [Google Scholar]

17. Amakama NJ, Knapp CW, Raimi MO, et al. Environmental fate of toxic volatile organics from oil spills in the Niger Delta Region, Nigeria. Int J Environ, Eng Edu. 2021;3(3):89-101.

    [Crossref] [Google Scholar]

18. Asiegbu OV, Ezekwe IC, Raimi MO. Assessing pesticides residue in water and fish and its health implications in the Ivo river basin of South-Eastern Nigeria. MOJ Public Health. 2022;11(4):136-42.

    [Google Scholar]

19. Isah HM, Raimi MO, Sawyerr HO. Patterns of chemical pesticide use and determinants of self-reported symptoms on farmer’s health: A case study in Kano state for Kura local government area of Nigeria. Res World Agric Econ. 2021;2(01):37-48.

    [Google Scholar]

20. Isah HM, Sawyerr HO, Raimi MO, et al. Assessment of commonly used pesticides and frequency of self-reported symptoms on farmers health in Kura, Kano State, Nigeria. J Edu Learn Manag. 2020;1(1):31-54.

    [Google Scholar]