Neil I. Ward

Multielement contamination of British motorway environments

Abstract The multielement content of vegetation, surface soil and dust samples collected along the M1, M6 and M25 motorways and analysed by inductively coupled plasma-source mass spectrometry (ICP-MS) is presented. A review is made of the elemental content of petrol and diesel. Analytical precision and accuracy was checked by analysis of IAEA Soil 5, NIST: SRM 1575 Pine Needles and NIST: SRM 1578 Orchard Leaves reference material with inter-analytical method comparison using neutron activation analysis (NAA). Eleven elements (V, Cr, Mn, Co, Ni, Cu, Zn, Br, Mo, Cd and Ce) clearly show elevated levels with increasing mean traffic density. For some elements the increase in magnitude is nearly 10-fold more than background values from the North Yorkshire Dales National Park and the Channel Island of Alderney. Elemental values for the M25 are generally higher than the M1 and M6 motorways. Enhanced elemental levels are related to traffic flow problems and thereby increased fuel consumption. Raised bromine levels are assumed to be related to the addition of ethylene dibromide — a lead scavenger — to petrol. The presence of other elements is associated with the wear of tyres and brake pads (Cd, Zn, Mn, Cu) the corrosion of welded metal plating (V, Ce, Ni, Cr) and the possible combustion of lubricating oils (Cd, Cu, V, Zn and Mo). Maximum elemental concentrations occur in surface soils indicating deposition of dust-borne particulates, splash and aerosol dispersion or motorway surface run-off. The multielement interactions in motorway environments is discussed.

Recent biological and environmental applications of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS)

Univ Estadual Paulista, UNESP, Unidade Diferenciada Sorocaba Ipero, BR-18087180 Sorocaba, SP, Brazil

Neutron activation analysis techniques for identifying elemental status in Alzheimer's disease

Brain tissue (hippocampus and cerebral cortex) from Alzheimers disease and control individuals sampled from Eastern Canada and the United Kingdom were analyzed for Ag, Al, As, B, Br, Ca, Cd, Co, Cr, Cs, Cu, Fe, Hg, I, K, La, Mg, Mn, Mo, Ni, Rb, S, Sb, Sc, Se, Si, Sn, Sr, Ti, V and Zn. Neutron activation analysis (thermal and prompt gamma-ray) methods were used. Highly significant differences (probability less than 0.005) for both study areas were shown between Alzheimers diesease (AD) and control (C) individuals: AD>C for Al, Br, Ca and S, and AD<C for Se, V and Zn. Aluminium content of brain tissue ranged from 3.605 to 21.738 μg/g d.w. (AD) and 0.379 to 4.768, μg/g d.w. (C). No statistical evidence of aluminium accumulation with age was noted. Possible zinc deficiency (specially for hippocampol tissue), was observed with zinc ranges of 31.42 to 57.91 μg/g d.w. (AD) and 37.31 to 87.10 μg/g d.w. (C), for Alzheimers disease patients.

Comparison of the heavy metal content of motorway stormwater following discharge into wet biofiltration and dry detention ponds along the London Orbital (M25) motorway

The Surrey section of the London Orbital M25 motorway uses mainly detention pond facilities for the treatment of stormwater runoff. A majority of these implement the use of dry detention basins. However, in a few locations biofiltration facilities operate through the use of reed bed systems. An assessment of the removal efficiencies for both wet biofiltration and dry pond treatment facilities was undertaken. Motorway-derived contaminants, including V, Cr, Mn, Co, Ni, Cu, Zn, Mo, Cd, Sb and Pb, were measured in unfiltered stormwater collected during the initial stages of a storm event using inductively coupled plasma mass spectrometry (ICP-MS). Results suggest that a higher level of motorway-derived heavy metal contamination exists in stormwater runoff from a road section with a higher average daily traffic density. In addition, a comparison of both sites shows a higher percentage removal efficiency of heavy metals in stormwater from the biofiltration facility.

The role of trace elements in male infertility

The elemental status of seminal plasma collected from four populations subdivided on the basis of sperm counts is presented. Elemental analysis was performed by inductively coupled plasma-source mass spectrometry (ICP-MS) for calcium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, nickel, lead, rubidium, selenium, vanadium, and zinc. The majority of elements reflected no statistically significant differences among the four groups. The role of trace elements in infertility may be more directly related to sperm and whole semen than seminal plasma levels.

Assessment of Chemical Factors in Relation to Child Hyperactivity

A questionnaire evaluation of 486 hyperactive children (HA) (82% boys, aged 7-13 years and 18% girls, aged 8-13 years) showed that more than 60% of cases reported a positive behavioural response (i.e. increased problems) in relation to consuming or being exposed to synthetic colourings and flavourings, food and beverage preservatives, cows milk and associated products, chemical detergents and perfume. In contrast, 172 sex- and age-matched control children (C) reported only 12% of cases responding to synthetic colourings and flavourings and chemical solvents. The main health problems reported by the 96% of hyperactive children affected by synthetic colourings and flavourings were persistent thirst problems, the development of eczema, ear and/or chest infections, and the production of excessive amounts of catarrh. Trace element measurements undertaken by inductively coupled plasma mass spectrometry showed that a low zinc and iron status is associated with hyperactive children when compared with control chi...

Enzymatic digestion for the determination of trace elements in blood serum by inductively coupled plasma mass spectrometry

A non-specific protease enzyme (pronase) was used to demonstrate the potential of enzymatic digestion as an alternative sample preparation method for the determination of trace elements in blood serum by ICP-MS. By measuring the number of peptide bonds in solution, it was found that this digestion led to a 40% reduction in the level of plasma protein in the samples. Based on the data obtained, it appears that the majority of these proteins were broken down into smaller polypeptides. Using this digestion technique, a high degree of instrument stability was achieved during the continuous analysis of blood serum over a 3 h period. Selective enhancement of the selenium signal was observed during these analyses. A charge-exchange mechanism between C + ions and selenium atoms in the plasma, which leads to the formation of excited Se + ions, is proposed and is supported by data related to the ionization/excitation energies of the various species involved in this reaction. It was also demonstrated that in order to achieve good accuracy, calibration must be conducted using matrix-matched standards. Finally, the accuracy of the technique is demonstrated by showing excellent agreement between the experimental results and the certified values for Seronorm certified serum reference material.

Trace elements in drinking and groundwater samples in southern Nigeria.

The levels of Al, Sn, Cs, Rb, Sr, Br, Cr, Mo, Co, Ba, Cu, Zn, Cd, Pb, Mn, Se, As, V and Ni were determined in drinking water supplies (public taps, domestic taps and treated water from public water sources) and groundwater supplies (boreholes and shallow wells) in some parts of Southern Nigeria. The water samples were analysed using inductively coupled plasma mass-spectrometry (ICP-MS). The mean levels (microgram/l) of all the elements ranged between 0.35 microgram/l for Cs and 87.3 micrograms/l for Zn in the drinking waters and between 0.54 microgram/l for Co and 420.3 micrograms/l for Ba in the groundwaters. A comparison of the elemental concentrations with WHO guidelines showed that with the exception of violations of Cd, Cr and Se limits in some of the drinking water samples, the levels of all the other elements investigated were below the WHO maximum allowable concentrations.

Traffic pollution: preliminary elemental characterisation of roadside dust in Lagos, Nigeria

Roadside dust collected from different parts of Lagos metropolis were analysed for heavy metals and other trace elements using a combination of instrumental neutron activation analysis (INAA), inductively coupled plasma-optical emission spectrometry (ICP-OES), and flame atomic absorption spectrometry (FAAS). The results show a positive correlation of the concentration of Pb and some other vehicular emission-related elements with the traffic density. Automotive emission was also found to be the main contributor to Pb concentration in the roadside dust but some elements which hitherto have been linked with automotive emission, such as cadmium and nickel, did not show any strong correlation with traffic density.

Comparison of selenium levels in pre-eclamptic and normal pregnancies

Abnormal placentation is the likely cause of the slow fetal growth and the high levels of circulating lipid peroxides found in severe preeclampsia. These peroxides are probably responsible for the high thromboxane:prostacyclin ratio found in this disease and may participate in the endothelial cell damage which is its most notable feature. Selenium (Se), because of its role in glutathione peroxidase, is suggested to be an important component of the removal system for these damaging peroxides. Serum-Se concentrations have therefore been measured in 19 pairs of pre-eclamptic women and matched controls. Infant birth-weights were recorded. No significant difference was found in the concentrations of Se in pre-eclamptic and control groups. Serum Se was found to be low in both groups. Birthweights were significantly lower in the pre-eclamptic group. The interpretation of serum-Se measurements from the third trimester of a pre-eclamptic pregnancy is complicated by the reduced fetal growth and probable lower Se take-up by the fetus in such a pregnancy. The merits of alternative measurements, such as total intravascular Se, placental Se, or samples from an earlier stage of gestation, are discussed. The importance of factors other than Se to the activity of glutathione peroxidase, and of other antioxidants to pre-eclampsia, is stressed.