Heavy Metal Contamination (Cu, Pb, Zn, Fe, and Mn) in Urban Dust and its Possible Ecological and Human Health Risk in Mexican Cities

Abstract

Cities occupy a relatively small percentage of the Earth’s surface. However, they influence the entire biosphere, affect biodiversity and environmental conditions, which end up affecting human health and well-being. Therefore, it is necessary to evaluate the level of contamination by heavy metals in urban environments, as well as the possible ecological and human health risks. In this study, the urban dust of six Mexican cities was analyzed and it was found that all studied cities were contaminated, except for Mérida, when soil world background value was used as reference. In contrast, Mérida and Morelia were the most contaminated when a local background was used (decile 1). The concentrations in the cities for the metals Cu, Pb and Zn, decreased in the order CDMX > San Luis Potosí > Toluca > Morelia-Ensenada > Mérida. In the particular case of Cu and Pb, SLP accompanied CDMX as the most polluted city. For Mn and Fe concentrations, the order was CDMX > Toluca > Ensenada > SLP > Morelia-Mérida. No potential ecological risk was found due to contamination by Cu, Pb, and Zn, in the urban dust of the studied cities. However, the higher metal contribution to the potential ecological risk in all the cities was from Pb; and it represented a moderate ecological risk of more than 25% on CDMX, SLP, and Toluca sites. Pb can also be a potential risk for children’s health. In addition, chronic exposure to Fe and Mn could trigger many ailments. In the future, it is important to identify the main sources of Pb in cities and seek mitigation strategies to reduce the possible adverse effects that this metal may be causing.

Environmental exposure to manganese and health risk assessment from personal sampling near an industrial source of airborne manganese

“…However, for the calculation of the risk associated with this pathway, the values used in the US EPA procedure (AR = 0.07 mg/cm 2 /day and SA = 5700 cm 2 ) may overestimate this exposure, since this AR value was derived after considering direct contact of skin with soil, as occurs in gardening activities (US EPA, 2011EPA, , 2004 and the skin surface area in contact with PM during most of the year is less than 5700 cm 2 . However, no alternative AR values have been found in the literature for PM adhered to skin; furthermore, the same methodology and AR values have been used to assess dermal risk linked to PM-bound pollutants in some studies (Aguilera et al, 2022;Al-Harbi et al, 2021;Fadel et al, 2022;Roy et al, 2022).…”

Assessment of Heavy Metal Contamination in Dust in Vilnius Schools: Source Identification, Pollution Levels, and Potential Health Risks for Children

“…Background values for indoor and outdoor dust have not been established in this investigation. Alternatively, Vilnius and global background values for soils have been used [ 8 ]. The contamination factor (CF) can be classified as follows: CF < 1 indicates low contamination, CF between 1 and 3 represents moderate contamination, CF between 3 and 6 indicates considerable contamination, and CF greater than 6 suggests very high contamination [ 32 ].…”

“…The contamination factor (CF) can be classified as follows: CF < 1 indicates low contamination, CF between 1 and 3 represents moderate contamination, CF between 3 and 6 indicates considerable contamination, and CF greater than 6 suggests very high contamination [ 32 ]. According to studies [ 8 , 32 ], these categories are founded on accepted environmental research standards and offer a methodical way to assess the degree of contamination in urban dust.…”

“…They can settle on impermeable surfaces within cities, including roads and roofs [ 4 , 5 , 6 , 7 ]. A global study, such as the analysis of urban dust in six Mexican cities, emphasizes the widespread presence of heavy metal pollution and its associated health hazards, particularly for children [ 8 ].…”

Elemental distribution and source analysis of atmospheric aerosols from Meycauayan, Bulacan, Philippines

“…Major anthropogenic and natural sources of heavy metals in atmospheric aerosols and urban dusts include industrial emissions, household and traffic effluents, weathering, and erosion [ 1 , 2 ]. The increasing population growth in urbanized cities leads to higher values of heavy metals as observed in different urban areas in Asia and the World [ [3] , [4] , [5] , [6] ].…”