Metal levels in indoor and outdoor dust in Riyadh, Saudi Arabia

Nursery Schools: Characterization of heavy metal content in indoor dust

“…wear and tear of vulcanized rubber tyres, lubricating oils and corrosion of galvanized vehicular parts (Li et al 2001;Al-Khashman, 2004;Adachi and Tainosho, 2004). The source of Cu, Cr and Ni in dust is believed to be from car components, tyre abrasion, lubricants corrosion of cars, engine wear, thrust bearing, brushing, bearing metals and brake dust respectively (Al Rahji and Seaward, 1996;Al-Khashman, 2004;2007). Although heavy metals in dust could be derived from indoor and outdoor sources, the result of this study indicated that major influence was from outdoor sources.…”

“…The locations of all nursery schools were close to the main road with high traffic density and therefore it is expected to contain high lead (Pb) (31.24 mg/kg) in indoor dust related to the automobile emission (Chattopadhyay et al, 2003). Pb is a universal pollutant in an urban environment due to automobile emission (Al Rahji and Seaward, 1996), and despite the gradual shift from leaded to unleaded petrol as fuel for automobile, it still remains as a major pollutant for some urban areas including Shah Alam city. Other metals such as Zn, Cu, Cr, Ni and Ba were also related to automobile emission.…”

“…Indoor dust is present in the indoor environment as a composite of particulate matter derived from interior and exterior sources. Dust can enter an indoor environment in several ways such as infiltration from outdoor sources and internally from smoking, incense burning, buildings and furniture materials, consumer products and occupant activities (Al-Rahji and Seaward, 1996;Turner & Simmonds, 2006). Indoor dust is a repository for environmental pollutants such as heavy metals that may accumulate indoors and is an important pathway of exposure to metal for humans.…”

“…A number of studies have suggested that there is a possibility that metals in the indoor dust can accumulate in humans, either directly or indirectly by inhalation, ingestion as a result of hand-to mouth activity or via dermal contact absorption (Al-Rahji & Seaward, 1996;Molhave et al, 2000). Young children, especially toddlers, can easily ingest soils or indoor dusts unintentionally since they spend most of their time indoors and much of this time is spent in contact with floors, engaging in mouthing of hands, toys and other objects or the consumption of food contaminated by hands (Mohd Tahir, 2007;Adekola & Dosumu, 2001).…”

An index to quantify street cleanliness

“…This means that significant human and financial efforts are devoted to cleaning the street network in order to control litter and to provide suitable aesthetic and sanitary conditions. Street deposits have been mostly sampled by sweeping [6,7], brushing [8,9], vacuum [10,11] or water flows, leading to the entry of water and pollutant loads into the combined sewer system [12]. However, the street cleanliness level is only one facet of a solid waste management system in which public education and public relations play critical roles [3].…”