Introduction Heavy metal contamination, without doubt, represents a major environmental threat due to toxic effect of metals and their invasion, and subsequent proliferation into the food chain, which results in serious ecological and health issues (Hrynkiewicz and Barum 2014). Contamination due to chemicals like heavy metals is a problem that may have a debilitating influence on the biosphere. The concentration of metals in our environments namely; air, water and soil are increasing at an exponential rate, with contributions mainly from different variety of industrial and domestic sources. The existing heavy metals in the industrial wastewater is a major global concern due to toxicity as well as persistence within the environment, thus necessitating physical extraction (Jina Tanzadeh, 2017). Currently, attention is turned to the biological removal of these recalcitrant heavy metals from the environment via the process known as an bioremediation. Bioremediation is a branch of environmental biotechnology used as alternative process for the removal of toxic contaminants from the environment (Maria et al., 2015). It is regarded as a cleaner, greener, cost-effective and environmentally friendly approach for removing pollutants and converting them into less toxic forms using microbes to degrade and detoxify hazardous substances (Maria et al., 2015). Bioremediation uses biological agents, mainly the conventional microbes to tidy up contaminated environments (Breisha et al., 2010). However and more recently, attention is shifted towards the use of halophilic microorganisms to accomplish this task. What are halophilic microbes? Halophilic microbes otherwise known as salt-loving or salt-tolerant microorganisms are organisms that thrive in an environment with extreme salinity. They are salt-loving organisms that live and thrive in environment with extreme salt concentrations that will destroy most other microbes. They can grow in a hypersaline environment and require a minimum of 0.2 M salt concentration for their growth and metabolism (Bhuva et al., 2013). These organisms can be isolated anywhere with a salt concentration ofsea water. Halophiles have been able to adapt to extreme physico-chemical situations because they have adopted certain molecular mechanisms that will enable them to thrive in such environments (Delgado-Garcia et al., 2012). They are either non-sporing rods or cocci, red to orange in colour. Generally, the salt concentrations in the surrounding environment greatly influence the morphology of the growing cells. Halophiles that can grow in various high concentrations of salt and at the same time survive in the absence of high salts are termed as halotolerant (Margesin and Schinner, 2001). Halophiles may be grouped into 5 main categories based on their salt requirement as; non-halophiles, slight halophiles, moderate halophiles, borderline extreme halophiles, and extreme halophiles (Arora et al., 2014). Bioremediation application of halophilic microbes Different traditional methods namely; membrane filtration, chemical precipitation, oxidation and/or reduction, evaporation, ion exchange, and electrochemical treatment process have been used to remove heavy metals from industrial wastewaters. However, these techniques are no longer favorable because of their high cost and ineffectiveness. Bioremediation which involves the use of biological materials to sequester heavy metals using a variety of strategies like bioaccumulation and biosorption is now considered inexpensive, considerably efficient and environmentally friendly alternative (Zmorrod et al., 2021). Microorganisms adopt different mechanisms such as biosorption, biotransformation of heavy metals into less toxic form, extrusion, exopolysaccharide production, and degradative enzymes for heavy metals bioremediation (Igiri et al., 2018 and Orji et al., 2021). Heavy metals are frequently found in saline and extreme saline environments because of evaporation in such environment, and also as a result of several industrial activities. Hence, some halophilic bacteria and archaea have developed tolerance to heavy metals. Several works (Sowmya et al., 2014, Amoozegar et al., 2012; Zmorrod et al., 2021; Orji et al., 2021) have reported the ability of halophilic microbes to tolerate and remove heavy metals from industrial effluents. These studies revealed the current trend andprospects of salt-tolerant microbes in bioremediation field. Conclusively, this short but informative research update provides valuable information for exploration and possible application of halophilic microorganisms in bioremediation technology for potential restoration of heavy metals contaminated saline environments.     References Amoozegar, M. A., Ghazanfari, N. and Didari, M. (2012). Lead and cadmium bio removal by Halomonas sp., an exopolysaccharide-producing halophilic bacterium. Progress in Biological Sciences. 2(1): 1-11. Arora, S., Vanza, M. J., Mehta, R., Bhuva, C. and Patel, P. N. (2014). Halophilic microbes for bio-remediation of salt affected soils. African Journal of Microbiology Research, 8(33), 3070–3078. Bhuva, C. G., Arora, S. and Rao, G. G. (2013). Efficacy of halophilic microbes for salt removal From coastal saline soils. National seminar with the theme: “microbes and woman welfare”, Bharathidasan University, Tiruchirappali, India. Bonete, M. J., Bautista, V., Esclapez, J., García-Bonete, M. J., Pire, C., Camacho, M. and Naofumi, (2015). New uses of haloarchaeal species in bioremediation processes. Advances in Biorem ediation of wastewater and polluted soil. 1st Ed. InTech, 23-49. Briesha, G.Z. and Winter, J. (2010). Bio – Removal of nitrogen from wastewaters – a review. J.             Am.Sci. 6(12): 508-528. Delgado‐García, M., Valdivia‐Urdiales, B., Aguilar‐González, C. N., Contreras‐Esquivel, J. C. and Rodríguez‐Herrera, R. (2012). Halophilic hydrolases as a new tool for the biotechnological industries. Journal of the Science of Food and Agriculture, 92(13), 2575–2580. Hrynkiewicz, K. and Baum, C. (2014). Application of microorganisms in bioremediation of             environment from heavy metals. Dorchrecht: Springer, 2115 – 27. Igiri, B. E., Okoduwa, S. I., Idoko, G. O., Akabuogu, E. P., Adeyi, A. O., and  Ejiogu, I. K. (2018). Toxicity and bioremediation of heavy metals contaminated ecosystem from tannery wastewater: a review. Journal of Toxicology; 2. https://doi.org/10.1155/2018/2568038.   Dr. Haliru Musa is a Lecturer II in the Department of Biological Science in Skyline University Nigeria. He holds a PhD in Bioprocess Engineering from Universiti Malaysia Perlis, Malaysia. You can join the conversation on Facebook @SkylineUniversityNG and on Twitter @SkylineUNigeria

Introduction Rapid urbanization and the growth of large cities in developing countries have been accompanied by the expansion of highly vulnerable urban communities living in informal settlements, many of which are on land exposed to extreme weather (IPCC 2014). Nigerian cities particularly Kano is among the cities in developing countries that experienced such expansion of communities living in an informal settlement and extreme weather, which the temperature reached 40 to 45 in °C between March and May. Concept of Urbanization  Urbanization is a process of population concentration that proceeds through the multiplication of points of concentration and the increase in the size of individual concentration seems quite appropriate (Barry, 1973). Hope and Lekorwe, (2009) defined urbanization as the annual rate of change of the percentage of people living in urban areas, or the difference between the growth rate of urban population and that of the total population. It is the process of transformation that affects geographic regions when they become more urban, and that during the processes of urbanization, a growing share of a region’s land and people become included in cities (Pivo, 1996). Environmental impacts Urbanization causes a lot of environmental impacts, in Nigeria two dimensions of impact can be identified thus; Site impact The wider regional impact Site impact These are negative effects of urbanization that are noticeable within each urban center. They are common to almost all towns and cities in Nigeria, they are;  Air and Noise Pollution Air pollution; Most of the gases and particles that people are subjected to while breathing air, came from combustion (burning) processes. That is the furnace in factories, homes, and office buildings, the engine in automobiles, airplanes and other motor vehicles, and the burning of garbage and trashes are the major sources of pollution from combustion. Pollution from these sources has a wide variety of effects. Noise pollution; Noise is the composite of many different sounds generated by human activities and it’s getting worse by the day. Audiologists reported that urbanization is the major source of noise. Part of this pollution results from population growth as there are more people making noise. In addition, homes and workplaces must be built and food has to be raised for a growing population. People need transportation to travel between home and workplaces. In their leisure time, they enjoy sport most especially watching football in view centers. All these needs and activities are further sources of noise. Solid waste problem Solid waste is probably the most visible form of pollution. People throw-away billions of tons of solid material each year. Much of these wastes end up littering roadsides and collecting in ugly dumps. These problems are most common in populated areas in and near cities. One of the common methods of disposal of solid waste in Nigeria is dumping, in which people simply dumped their wastes on open ground. Wider regional impact Urban regional impact is a reflection of the enormous demand which urban center make on regional resources. These includes; Fuel wood demand, Road construction demand and Building materials demand. Fuel wood is brought into the urban center from the surrounding regions on a daily basis. It is extracted from the farms and dead trees in the forest. Increasingly, live trees are being cutting down daily and their stems are converting into fuel wood. This demand increase with the rise in level of urban poverty and with ever increasing of price of kerosene. Urban road network construction requires laterite, sand and gravels, which are obtained from quarries in the surrounding areas. The quarries are often abandoned later and become gullies or stagnant water ponds. Slumping, collapsed valley and roadsides are also associated with these quarries. Lastly, the bulk of materials needed for construction of building in cities like Kano are derived from the surrounding regions. These materials include sand, gravels, stones and wood. Excavation of sand, gravels, and stones create menacing quarries in the environment. Conclusion It could be concluded that the demand made by urban centers on the resources of their surrounding areas has led to indiscriminate exploitation of these resources and therefore, environmental degradation policies and measures must be spelled out and implemented to guide the behavior of urban dwellers and the exploitation of environmental resources. Recommendations Firstly, Programmeme of education and awareness aimed at bringing about attitude change with regards to environmental sanitation is highly recommended. Secondly, a waste management board and not just an environmental sanitation agency is highly needed for our urban center. Thirdly, land use regulations in the urban centers should be adhered to. When activities are carried out in their proper and district locations, the result is a clean healthy and beautiful environment devoid of conflicts. Reference Berry B. J. L. (1973), Human consequences of urbanization. The University of Chicago Press. Hope K. R. and M. Lekorwe, (2009). Urbanization and the Environment in Southern Africa: Towards a Managed Framework for the Sustainability of Cities. Journ. Environ. Plann. Mgt. 42:6. 837–59. IPCC, (2014), Climate Change 2014: Impacts, adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of working group II to the fifth Assessment Report of the Intergovernmental panel on climate change. Cambridge University Press, 1132pp. Pivo, G. (1996). Towards Sustainable Urbanization on Main-street Cascadia Cities. Int. Journ. of Urb. Policy and Plan. 13:5, 1314 – 1319.   Aliyu Mohammed Lawan is a Lecturer II in the Department of Geology in Skyline University Nigeria. He holds a Master’s degree in Applied Geophysics from Ahmadu Bello University, Zaria. You can join the conversation on Facebook @SkylineUniversityNG and on Twitter @SkylineUNigeria