Exposure scenarios and guidance values for urban soil pollutants.

In general, risk assessments of urban soil pollution are prepared by comparing the levels of pollutants with soil quality criteria. However, large urban areas are contaminated with concentrations of pollutants far exceeding the existing soil quality criteria and would consequently be considered to be of potential risk to humans. This is, however, a rather rigid approach, and for risk management purposes it would be desirable to have more than just one level of soil quality criteria. Therefore, a generic risk assessment model was developed for five different use scenarios: child-care centers, kitchen gardens, ornamental gardens, parks, and sports grounds. In each of the scenarios, three different types of expected behavior are described for children and adults, respectively, resulting in different levels of exposure to the pollutants. For risk management purposes, various guidance values can then be derived for each use scenario. Below a lower guidance value, a free use of the area according to the defined use is possible without an unacceptable risk to the public. Above an upper value, a cutoff of the exposure is necessary. In between, the use may be regulated by different types of advice. The model is still preliminary but was, however, used for derivation of guidance values for five commonly found soil pollutants, of which the results for benzo[a]pyrene and lead are presented.

Ultrasonic testicular texture and size in 444 men from the general population: correlation to semen quality.

Scrotal ultrasonography was performed in 888 testes of 444 randomly selected men appearing before the medical board prior to military service (Mili group, 287 men, median age 18.8 years), and in employees from an industrial company (Empl group, 157 men, median age 35.6 years). The ultrasonic volume of each testis was calculated from 3 perpendicular measurements. The ultrasonic texture on sectional planes was scored using a scale from 1 to 5, 1 being very regular, 2 slightly irregular, 3 moderately irregular, 4 very irregular or with bright echogenic points, and 5 with demarcated tumor suspicious areas. Orchidometer measurements were performed in 258 men in Mili group, and semen samples were obtained from 121 men in Empl group. The ultrasonic volume of the right testis (median 14.1 ml, range 3.0-31.4 ml) was bigger than that of the left testis (median 13.0 ml, range 3.5-35.2). The volume was dependent on age for men under 20 years, but not for men aged 20 years or more. The subgroup of men with a history of cryptorchidism had a smaller average testicular volume (median 10.5 ml) compared with men with normal descent (median 14.1 ml). Ultrasonic volume was positively correlated to the total sperm count in the ejaculate, to sperm penetration in egg white, and to normal sperm morphology. The echo score distribution showed slightly higher scores in Empl for both the right and the left testis. Men in Empl group were older, and it could not be precluded that this difference was due to age.(ABSTRACT TRUNCATED AT 250 WORDS)

Waterborne paints. A review of their chemistry and toxicology and the results of determinations made during their use.

This work presents information on the composition of waterborne construction paints used in Denmark, data from determinations of chemicals evaporating from paints applied with a brush or roller, and the toxicology of these chemicals. Seven product types were selected to illustrate the composition of the paints. Measurements at two workplaces were used as models for the work environment during painting. Evaporating chemicals were collected on Tenax TA and analyzed with capillary column gas chromatography after thermal desorption. In smudging work, waterborne paints may result in skin irritation and/or sensitization when safety precautions are not taken. Irritation of the mucous membranes may be expected if airing is not sufficient. This irritation may lead to headache mediated by trigeminal nerve stimulation. No other health hazards (eg, brain damage) are expected. The available information indicates that waterborne paints are a clear improvement over traditional paints which use white spirit as the main solvent.

Biochemical pattern in experimental exposure of humans to white spirit. I. The effects of a 6 hours single dose.

The effect of 6 hrs single exposure to white spirit on the concentration of S-alpha-amylase, S-cholesterol, S-triglyceride, S-sodium, S-potassium, S-creatine kinase, S-orosomucoid, S-urate, and S-glucose was analysed in 12 volunteers 6 and 48 hrs after start of exposure. After exposure to 0 p.p.m. and 100 p.p.m. of each of three white spirits containing 99% paraffins or 52% paraffins and 48% naphthenes, or 57% paraffins, 25% naphthenes and 18% aromatics, respectively, the only significant changes were a decrease in S-alpha-amylase concentration and S-Potassium concentration by 9% (P less than 0.05) 48 hrs after exposure to the white spirit high in naphthenes. This type also caused the highest blood concentration. In a subsequent study on exposure to 0, 50, 100, and 200 p.p.m. of the spirit high in naphthenes the only significant dose-response relationship was that the concentration of S-alpha-amylase decreased 7% (P less than 0.05) after 6 hrs, and S-urate decreased 4% (P less than 0.05%) after 48 hrs as the doses increased. No changes in subjective symptoms were found. Thus, even at low levels, white spirit high in naphthenes appears to result in subtle biological effects prior to the appearance of symptoms of poisoning.

Kinetics of white spirit in human fat and blood during short-term experimental exposure.

Seven volunteers were exposed to 100 p.p.m. white spirit (99% paraffins C8-C12) 6 hrs daily in 5 days. The mean concentration of white spirit after 5 days of exposure was 41.1 mg/kg fat (Friday afternoon). On the following Monday morning, the concentration was 31.7 mg/kg, i.e. only 23% had been eliminated during the exposure-free weekend. The estimated mean and median half-life was 7 and 8 days, respectively, elimination rate constant 0.0039 and 0.0036 hrs-1, time to reach steady state 5 to 8 weeks, maximal and minimal steady state concentration 85 and 66 mg/kg and 66 and 52 mg/kg, respectively. The concentration of white spirit in fat found each afternoon correlated significantly with the total dose. The concentration of white spirit/kg fat correlated positively with serum triglyceride and inversely with the percentage body fat (not significantly). The concentration of white spirit in the brain at steady state was estimated to maximum 11 mg/kg, while the half-life in the brain was estimated to maximum 18-19 hours. Minor differences occurred in the spectrometrical pattern produced by the in vivo biopsy evaporate as compared to in vitro specimens and white spirit vapours per se, thus indicating that the white spirit was slightly biotransformed or that the approximately 200 constituents of white spirit were absorbed differently. Thus, during exposure at the threshold limit value level, white spirit is accumulated in depot fat over weekends and in brain over working days. However, white spirit is almost eliminated from the brain during weekends.

Biochemical pattern in experimental exposure of humans to white spirit. II. The effects of repetitive exposures.

The concentration of P-immunoglobulins (P-IgG, P-IgA, P-IgM), P-orosomucoid, S-creatine kinase (S-CK), and S-follicle stimulating hormone (S-FSH) was investigated in seven subjects exposed to 100 p.p.m. white spirit, 6 hrs daily during 5 days while 5 subjects were used as unexposed controls. The mean values for S-CK concentration in the exposed group increased significantly with 59% and 76% above the base-line (O-hr value) 96 hrs and 168 hrs, respectively, after the start of the exposure (P less than 0.05), while the mean values for S-FSH concentration decreased significantly to 11% and 9% below the base-line after 24 hrs and 96 hrs (P less than 0.05), respectively. S-CK concentration and S-FSH concentration in the control group remained unchanged. A marked interindividual and intraindividual variance in S-CK concentration and S-FSH concentration was observed. No changes in the concentration of immunoglobulins and orosomucoid were observed in both groups during the experiment. The mechanisms for the changes are at present only speculative, but solvent induced changes in muscle cell membranes with subsequent enzyme leakage seem the most reasonable explanation for the increase in S-CK concentration, while an effect on the hypothalamic FSH releasing hormone may explain the decrease in S-FSH concentration.

N-hexane and its toxicologic effects: a review.

This review is a critical survey and evaluation of the recent literature relevant as medical background for a discussion of hygienic threshold values for hexane. Polyneuropathy and maculopathy, as well as subclinical effects, e.g., functional disturbances (conduction velocity of the motor and sensory nerves), are included.

Alcohol elimination rate after inhalation of oxitol(2-ethoxyethanol).

A 39-year-old man, accused of driving a car under the influence of ethanol, claimed that the use of an oxitol-containing floor lacquer prior to the drive might have enhanced the concentration of ethanol. Since oxitol has a higher affinity to alcohol dehydrogenase than ethanol, interaction could not be excluded primarily. With the client's informed consent 104 g of ethanol was given orally in a chamber at exposure to 0 ppm and 316 ppm oxitol, respectively. No difference in the elimination rate of ethanol was found. After combined exposure to oxitol and ethanol a decrease of the neutrophilocytes and the thrombocytes was found, as well as an increase of the serum creatine kinase. After exposure solely to ethanol, there were no abnormal blood sample changes.