Urban Soils and Road Dust—Civilization Effects and Metal Pollution—A Review

Abstract

Urban soils have been changed much by human impacts in terms of structure, composition and use. This review paper gives a general introduction into changes from compaction, mixing, water retention, nutrient inputs, sealing, gardening, and pollution. Because pollutions in particular have caused concerns in the past, metal pollutions and platinum group metal inputs have been treated in more detail. Though it is not possible to cover the entire literature done on this field, it has been tried to give examples from all continents, regarding geochemical background levels. Urban metal soil pollution depends on the age of the settlement, current emissions from traffic and industry, and washout. It seems that in regions of high precipitation, pollutants are swept away to the watershed, leaving the soils less polluted than in Europe. Health hazards, however, are caused by ingestion and inhalation, which are higher in 3rd world countries, and not by concentrations met in urban soils as such; these are not treated within this paper in detail. With respect to pollutants, this paper is focused on metals. Contrary to many reviews of the past, which mix all data into one column, like sampling depth, sieved grain sizes, digestion and determination methods, these have been considered, because this might lead to considerable interpretation changes. Because many datasets are not Gaussian distributed, medians and concentration ranges are given, wherever possible. Urban dust contains about two to three fold the hazardous metal concentrations met in urban soils. Some data about metal mobilities obtained from selective and sequential leaching procedures, are also added. Soil compaction, pollution, sealings and run-offs cause stress situations for green plants growing at roadside locations, which is discussed in the Section 5. Environmental protection measures have led to decrease metal pollutions within the last decade in many places.

Influence of Urban Informal Settlements on Trace Element Accumulation in Road Dust and Their Possible Health Implications in Ekurhuleni Metropolitan Municipality, South Africa

“…Furthermore, the dumping of waste in any available space or adjacent to the streets may release elements such as Ba. Waste materials such as ceramics, glass, or plastics are considered to be possible sources of Ba [ 43 ]. Tires and brakes are also sources of Ba.…”

Socio-Environmental Determinants and Human Health Exposures in Arid and Semi-Arid Zones of Iran—Narrative Review

“…Moreover, lack of public awareness and transparency legislation, inappropriate public transport, lack of services such as proper management of transport, paved roads and primitive roads and unplanned distribution of industries contribute to increase the impact air pollution on the incidence of diseases due to raise the chances of exposures. 49 , 50 Despite this situation, there is not regular data monitoring of those hazardous elements such as air toxics chemicals and also it has lacked a strong communication campaign. There are several reports about long term and short-term health effects of PM around the world 51 - 53 but there is limited publication has been reported about Iran.…”

Identification of Metal Contamination Sources and Evaluation of the Anthropogenic Effects in Soils near Traffic-Related Facilities

“…A small amount of As has been used for Pb component enhancement in car batteries, and As has been known to be present in brake and fuel [64,65]. Ni could be emitted from tire wear and motor/engine oil spills [65][66][67][68]. However, Ni and As concentrations contained in the fuel, tires, and brakes were considerably lower than that of Zn, Pb, and Cu.…”