Effect of lead from motor‐vehicle exhausts on plant and soil along a major thoroughfare in Baroda city

Ambiental dust speciation and metal content variation in TSP, PM 10 and PM 2.5 in urban atmospheric air of Harare (Zimbabwe)

Levels of TSP, PM(10) and PM(2.5) as well as levels of Pb, Co, Ni and Cd in TSP, PM(10) and PM(2.5) have been determined in atmospheric particulates collected at Loius Mountbatten School (Harare). The samples were collected for a period of 6 months from July to December 2002. The average levels of TSP, PM(10) and PM(2.5) measured at the site are 106.11, 59.70 and 40.55 mg m(-3) respectively. The average level of TSP at Loius Mountbatten School is 106.11 mg m(-3), which is higher than the annual WHO guideline limit of 90 mg m(-3). The average level of PM(10) measured at Loius Mountbatten School is 59.70 mg m(-3), and is higher than the US-EPA and UK-EU guideline limit of 50 mg m(-3). The average level of PM(2.5) measured at the site are also higher than the WHO and US-EPA annual guideline limit of 15 mg m(-3). The analysis of metal concentrations in TSP, PM(10) and PM(2.5) was done using Graphite Furnace Atomic Absorption Spectrometry (GFAAS). The analysis showed the following average elemental concentrations: 0.157 mg Pb m(-3) in TSP, 0.166 mg Pb m(-3) in PM(10), 0.185 mg Pb m(-3) in PM(2.5), 0.009 mg Co m(-3) in TSP, 0.007 mg Co m(-3) in PM(10), 0.011 mg Co m(-3) in PM(2.5), 0.223 mg Ni m(-3) in TSP, 0.166 mg Ni m(-3) in PM(10), 0.180 mg Ni m(-3) in PM(2.5) and 0.005 mg Cd m(-3) in TSP, 0.006 mg Cd m(-3) in PM(10), 0.005 mg Cd m(-3) in PM(2.5). The levels of Pb and Ni were generally higher than those of Co and Cd and this could have been due to high traffic volumes and various industrial activities in the Workington Industrial Area.

Analysis of lead in soils adjacent to an interstate highway in Tampa, Florida

In order to assess the amount and distribution of lead pollution in soils adjacent to a major interstate highway serving the city of Tampa, Florida, a total of 224 samples were collected from 32 transects perpendicular to the roadway. The lead content was measured using atomic absorption spectrophotometry. The highest levels of lead were found at distances of 81, 243, and 729 cm from the road. The results show that there is a weak negative correlation between soil lead and the distance from the roadside, as well as with traffic density. The weakness of the relationship is a result of confounding variables such as turbulence and other microclimatic factors, downslope movement of soils overtime, and human action such as construction and highway landscaping. Nevertheless, over one-third of the samples collected in the study area contain more than 500 μg g(-1) lead, levels considered to be hazardous by the United States Centers for Disease Control and the Environmental Protection Agency.

Soil lead levels in a small town environment: a case study from Mt Pleasant, Michigan

Few studies are made on the potential soil Pb burden for a small city in rural environment. Data obtained by atomic absorption spectrophotometry suggest a somewhat weak significant positive relationship (r=0.27) between increased traffic volume and roadside soil Pb content. Median soil Pb levels along the most heavily travelled roads are 320 microg g(-1) while background concentrations are 200 microg g(-1). No significant relationship is found between predominant wind direction and soil Pb content. Zones where cars idle have only slightly elevated Pb levels. Older homes have soil Pb values exceeding 1000 microg g(-1); a significant positive relationship (r=0.59) exists between increasing soil Pb and home age. Schools, which are mainly located away from heavily travelled roads and typically of brick construction, have soil Pb concentrations at background levels. In general, the small city Pb burden is lower than in major urban areas. However, soils around older homes and in special locales, such as salvage yards, have Pb levels comparable to major urban areas.