R. Sadler

Public Health Risks from Heavy Metals and Metalloids Present in Traditional Chinese Medicines

Out of 247 traditional Chinese medicines (TCM) investigated, a proportion were contaminated with arsenic (5–15%), lead (∼5%), and mercury (∼65%). Some preparations exceeded the tolerable daily intake (TDI) for males and females for arsenic (4 and 5 products, respectively), lead (1 and 2 products), and mercury (5 and 7 products). These exceedances were as high as 2760-fold, which posed a potential danger to public health. As many users are known to self-prescribe, there is a substantial risk of poisoning from the consumption of these contaminated TCM.

PCDDs, PCDFs, PCBs and HCB in marine and estuarine sediments from Queensland, Australia

Concentrations of 2,3,7,8-chlorine substituted PCDDs, PCDFs, selected PCB congeners and HCB were determined in sediment samples collected from sites along the east coast of Queensland in northern Australia. PCDDs were detectable in all sediment samples while PCDFs, PCBs and HCB were mainly found in sediment samples collected from sites in the Brisbane metropolitan area. The results provide evidence that an unidentified source for higher chlorinated PCDDs exists along the Queensland coast.

Environmental modification of PAH composition in coal tar containing samples

Abstract The PAH composition of coal tar containing samples collected at a number of coal gasworks sites has been studied. Samples were removed from areas where the coal tar components would have undergone varying degrees of environmental modification since deposition. The degree of environmental modification for individual PAHs exhibits a strong correlation with various molecular descriptors including octanol/water partition coefficient (KOW). Regression lines for environmental modification ratio-descriptor relationships show an increasing slope with increasing environmental attenuation of the coal tar sample. Aqueous partitioning and volatilization are probably the main processes which control environmental modification of coal tar at gasworks sites. The application of molecular descriptors shows promise for modelling the environmental behaviour of PAHs in these situations.

CONTAMINANTS IN SOIL AS A RESULT OF LEACHING FROM ASPHALT

Significant concentrations of PAHs and hydrocarbons were recorded in soil, beneath an asphalt cover. The site had not received any significant inputs from internal combustion vehicles and hence the contaminants would appear to have originated through leaching from the asphalt surface. PAH concentration in the soil samples was positively correlated with the moisture content at the site. A direct logarithmic relationship could be demonstrated between soil content of a particular PAH and molecular properties such as water solubility. The ratios between individual PAH concentrations at sites which had undergone different degrees of leaching also showed a linear logarithmic relationship to molecular descriptors such as connectivity index. It is suggested that a significant amount of PAH can enter the environment through leaching from asphalt surfaces. At least some of the roadside PAH contamination probably results from this pathway, in addition to deposition from exhaust fumes.

Bioaccumulation of organochlorine pesticides from contaminated soil by cattle

The study aimed to quantitate the uptake by beef cattle of organochlorine pesticides in from soil. Although such uptake is known to occur, uptake rates have not been accurately measured for these animals and cannot be inferred from data obtained with dairy cattle. In this study, cattle received a diet, of a standard feedlot ration supplemented with organochlorine-pesticide (aldrin + dieldrin) contaminated soil. The levels of pesticides in the feed would approximate uptake through normal grazing. Samples of the subcutaneous fat were removed periodically and analysed for pesticide content. Uptake of dieldrin (but not other pesticides present in the soil) was rapid and substantial. Uptake from sandy soils was more efficient than that from clay soils. The experiment was terminated after 8 weeks, because of the high levels of dieldrin in the tissues. Depuration of the accumulated pesticides was a slow and complex process, requiring a longer period than accumulation.

Direct examination of cadmium bonding in rat tissues dosed with mine wastes and cadmium-containing solutions

Direct examination by XANES and EXAFS of metal bonding in tissue can be demonstrated by examining cadmium uptake and bonding in animal tissue maintained at cryogenic temperatures. XANES at the K‐edge of cadmium were collected at the Photon Factory Advanced Ring (PF‐AR), NW10A beam line at KEK‐Tsukuba‐Japan. Rats fed with 1g mine waste containing 8–400 mg/kg cadmium per 200g body weight (b.w.) or dosed by oral gavage with either cadmium chloride solution alone (at 6 mg/kg b.w.) or in combination with other salts (As, Cu or Zn), 5 days/week for 6 weeks, had 0.1–7.5 and 8–86 mg/kg cadmium in the liver or kidney, respectively. Rats given intraperitoneally (ip) or intravenously (iv) 1–4 times with 1 mg/kg b.w. cadmium solution had 30–120 mg/kg cadmium in the liver or kidney. Tissues from rats were kept and transferred at cryogenic temperature and XANES were recorded at 20 K. The spectra for rat liver samples suggested conjugation of cadmium with glutathione or association with the sulfide bond (Cd‐S) of protei...

chromatographic behavior of PAHs in moist sandy soils.

The transport of polycyclic aromatic hydrocarbons (PAHs) in sandy soils has been studied. In this study, the PAHs were derived from a creosote‐based wood preservative applied to wooden power poles. The observed pattern of distribution differed from that in clay soils, and even the high molecular weight PAHs showed some mobility. In moist soils, PAHs showed a chromatographic separation according to molecular weight, with the smallest molecules moving the greatest distance into the soil profile. Under these conditions, the soil may be considered as a chromatography column and a column capacity factor calculated for the separation of each individual PAH. In this manner, it is possible to relate the movement of these molecules in sandy soil to physicochemical properties and molecular descriptors. First order connectivity index showed the best correlation with transport of PAHs in moist sandy soil.