Due to differences in regulation, production techniques, and heavy industrial use in the past, it is difficult to attract those willing to tackle the uncertainty and obstacles associated with potential clean up.<ref>{{Cite journal|last1=Trouw|first1=Michael|last2=Weiler|first2=Stephan|last3=Silverstein|first3=Jesse|date=2020-03-06|title=Brownfield Development: Uncertainty, Asymmetric Information, and Risk Premia|journal=Sustainability|volume=12|issue=5|pages=2046|doi=10.3390/su12052046|issn=2071-1050|doi-access=free}}</ref> Sites that are contaminated can cause public health risks, including physical risks like uncovered holes, unsafe structures, and sharp objects. Past industrial activities can leave behind chemical contamination, and people may become exposed to these chemicals when entering the properties.<ref>{{Cite web|date=June 2005|title=Public Health and BrownfieldsIn Wisconsin|url=https://www.dhs.wisconsin.gov/publications/p4/p44980.pdf|url-status=live}}</ref> Sites that have high levels of land contamination have a high cost of remediation. [[Nature-based solutions]] is an idea being talked about to produce a more environmental space. Nature-based solutions can be looked at as policies and approaches to environmental issues that are in benefit to human health and biodiversity.<ref>{{Cite journal|last1=Song|first1=Yinan|last2=Kirkwood|first2=Niall|last3=Maksimović|first3=Čedo|last4=Zheng|first4=Xiaodi|last5=O'Connor|first5=David|last6=Jin|first6=Yuanliang|last7=Hou|first7=Deyi|date=2019-05-01|title=Nature based solutions for contaminated land remediation and brownfield redevelopment in cities: A review|url=http://www.sciencedirect.com/science/article/pii/S0048969719303985|journal=Science of the Total Environment|language=en|volume=663|pages=568–579|doi=10.1016/j.scitotenv.2019.01.347|pmid=30726765|bibcode=2019ScTEn.663..568S|issn=0048-9697}}</ref> These nature-based solutions promote environmentally friendly strategies instead of your regular industrial approaches that have climate hazards.{{Citation needed|date=April 2020}} An example would include developing a permeable green area, from these brownfield sites. [[Phytoremediation]] is another environmentally friendly approach for brownfield remediation.<ref name=":15">{{Cite web|url=https://www.sciencedirect.com/topics/earth-and-planetary-sciences/phytoremediation|title=Phytoremediation - an overview {{!}} ScienceDirect Topics|website=www.sciencedirect.com|access-date=2020-04-01}}</ref> Phytoremediation programs reduce contaminants in the soil, water and air through planting different types of plants. Important metals that are harmful to human health, such as [[selenium]], [[zinc]], [[nickel]] and iron, are removed from contaminated soil through this process. These procedures are inexpensive because the plants rely on sunlight and the recycled nutrients in the ground. Although, phytoremediation cannot be used the same way in every destination due to different types of plants being nurtured differently in different types of environments.<ref>{{Cite journal|last1=Westphal|first1=Lynne M.|last2=Isebrands|first2=J. G.|date=2001|title=Phytoremediation of Chicago's brownfields: consideration of ecological approaches and social issues.|url=https://www.fs.usda.gov/treesearch/pubs/12487|journal=In: Brownfields 2001 Proceedings; Chicago, II.|language=en}}</ref> It depends on the soil, where the plant is placed, if it is getting enough nutrients to thrive, etc. The plants end up being so greatly polluted from heavy metals that they need to be disposed of. Thermal treatment is used as a disposal option. Thermal treatment implicates the combustion of the waste materials through machines that produce high enough temperatures, which decomposes the organic molecules within the plant. This treatment is typically used in the residential and industrial scale, making it useful for brownfield sites.<ref>{{Cite journal|last1=Kovacs|first1=Helga|last2=Szemmelveisz|first2=Katalin|date=2017-01-01|title=Disposal options for polluted plants grown on heavy metal contaminated brownfield lands – A review|url=http://www.sciencedirect.com/science/article/pii/S0045653516312747|journal=Chemosphere|language=en|volume=166|pages=8–20|doi=10.1016/j.chemosphere.2016.09.076|pmid=27681256|bibcode=2017Chmsp.166....8K|issn=0045-6535}}</ref>
