The difference in effect on acidification and species of aluminum speciation between HNO₃ and H₂SO₄for two contrasting types of soils in surface charge was investigated. The results show that the effect of H₂SO₄ on acidification of variable charge soils (Ferric Acrisol and Haplic Acrisol) of subtropical regions wasweaker than that of HNO₃, due to the specific adsorption of SO₄ ²⁻ and the accompanied release of OH⁻. For two constant charge soils, Haplic Luvisol andEutric Cambisol, the difference in effect between the two acids is small. The concentrations of total inorganic monomeric aluminum, Al³⁺, Al-F complexes and Al-SO₄complexes in the extract from variable charge soils are alsolower in H₂SO₄ systems than those in HNO₃ systems, whereas the reverse is true for constant charge soils, except the concentration of Al³⁺. For variable charge soils, Al-F complexes are the major species of inorganic monomeric aluminum at high pH butAl³⁺ might contribute to a largepart at low pH, while for constant charge soils Al-F complexes contribute almost exclusively to the inorganic monomeric aluminum. The presence of a large amount of SO₄ ²⁻ in the extract from the constant charge soilsleads to a higher proportion of Al-SO₄ complexes in totalinorganic monomeric aluminum than that from variable charge soil, although the numerical value of proportion is small.

Roads play a major role intransporting sediment associated nonpoint sourcepollutants to urban stream networks via storm drains. In urban areas the relationship of erodible soil toroads may be of critical importance in controllingmetal contributions to roads. Two 50-m transects(Park and School) were investigated perpendicular toroads in Manoa basin, Oahu, Hawaii. Concentrations ofnine elements were compared to background control soillocations and to five supplemental samples from nearbyrecreational parks. Sediment from curbside areas ofroads (road deposited sediment) was collected as thestarting point of each transect, and subsequently soilwas sampled from two depths (0–2.5 cm and 7.5–10.0 cm)along the transects. Total and 0.5 M HCl extractableconcentrations were determined for aluminum (Al),calcium (Ca), chromium (Cr), copper (Cu), iron (Fe),manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn)using either inductively coupled plasma-atomicemission spectroscopy (ICP-AES) or flame atomicemission spectroscopy (FAAS). Ca, Cu, Pb and Znexhibited anthropogenic enhancement, with Pb and Znhaving the greatest enrichment in road sedimentfollowed by locations nearest the road. Copperdisplayed a narrower band of contamination than eitherPb or Zn, and this may reflect larger aerosolassociations and more rapid fall velocities. Lead andZn exhibited substantial decay in concentration at 50 m compared to the road sediment, but enrichment wasstill apparent. The positioning of a band of soilbetween the road-curb area and the sidewalk for thePark transect facilitated deposition and storage oftrace metals, and with subsequent erosion by splash orconcentrated flow this area can account for continuedtransport of contaminated sediment to adjacent roadsurfaces. On the other hand the School transect hadno soil directly beside the road, and the nearestsample from the road (5 m) displayed enrichment butsubstantially lower than the Park transect. Thesepreliminary data suggest that remobilization of soilstored metals in close proximity to roads cansignificantly prolong the environmental contaminationof urban road systems and eventually stream sediments.

Six seaweed species of the Rhodophyta family were sampled for atwo-year period from June 1996 to August 1998 along the Atlanticcoast of Ghana (part of the Atlantic Ocean). The species wereanalysed to determine the levels of eleven chemicalelements namely: Al, As, Br, Cd, Fe, La, Mn, Ni, Hg, V and Zn byInstrumental Neutron Activation Analysis (INAA). Al, Br, Ni, andZn were measured in all the seaweed species studied. The elementAl generally showed the highest concentrations in most of thespecies analysed while Hg levels were the lowest. Precision andaccuracy of the method have been evaluated and the detectionlimits also calculated. The results showed high variability inand between species, among sampling sites and times ofcollection. The high values of metal concentrations in themacroalgae suggest that these marine organisms can be used asbiological indicators for studing marine pollution.