Urinary mandelic acid concentration after occupational exposure to styrene and its use as a biological exposure test.

LOF A, LUNDGREN E, NYDAHL E-M, BYFALTNORDQVIST M. Biological monitoring of styrene metabolites in blood. Scand J Work Environ Health (1986) 70-74. Ten men occupationally exposed to styrene in two glass-fiber reinforced plastics factories were studied during three consecutive workdays. The mean external exposure level was 99 mg/m", The total pulmonary uptake of styrene was estimated from measurements of the styreneconcentrationin inspiredair, the pulmonary ventilation,and the relative uptake. A gas chromatographic method based on electron capture detection was used to quantify styrene glycol,as wellas styrene-7,8-oxide, in blood. The concentration of styrene glycolappeared to be linearly related to the preceding uptake of styrene. When the uptake during 5 h immediately before the blood sampling was considered, the correlation coefficient (r) obtained the value of 0.90. The concentration of styrene-7,8-oxide wasat the detection limitof 0.02Itmolllin most samples. A weakercorrelationbetween the concentration of styrene in blood and the uptake during the hour immediately preceding the blood sampling was obtained (r=0.71).

Section: Styrene Concentration In Bloodsupporting

confidence: 72%

Biological monitoring of styrene metabolites in blood.

Löf¹,

Lundgren²,

Em³

et al. 1986

“…(6) and in the surveys of styrene in ,adilpose ti'ssue from this lahoratory, the limit proposed by Linch (8) is exoeeded, in some oases to a considerable degree. Lt is evident that conditions exist for accumulation of styrene in the body during occupational exposure.…”

mentioning

confidence: 90%

Exposure to styrene in a polymerization plant. Uptake in the organism and concentration in subcutaneous adipose tissue.

Engström¹,

Åstrand²,

Wigaeus³

1978

Exposure to styrene in a polymerization plant. Uptake in the organism and concentration in subcutaneous adipose tissue. by Engström J, Åstrand I, Wigaeus E 4 (1978) 324-329. Three male employees exposed to styrene in the processing of polyester tanks were studied during a work week. From Tuesday to Friday the concentration of styrene in ambient air was measured continuously in the breathing zone. The uptake in the organism was estimated as the product of the time-weighted average of the concentration in inspiratory air, the time-weighted average of 8-h pulmonary ventilation, and the percentage pulmonary uptake. Pulmonary ventilation was measured with the Wright respirometer. Percentage pulmonary uptake was estimated on the basis of the concentrations in inspiratory and alveolar air. The amount of body fat was estimated by an anthropometric method. The concentration of styrene in subcutaneous adipose tissue was determined by gas chromatography after needle biopsy before and after the workshift on Monday, Wednesday and Friday. The time-weighted average of the concentration of styrene in inspiratory air during the work week was 32-85 mg/m s , Le., below half of the Swedish threshold limit value (210 mg/m 3 ). The mean daily uptake in the organism was 193-558 mg. On Monday morning the concentration of styrene in adipose tissue was 2.8-8.1 mg/kg and on Friday afternoon 4.7-11.6 mg/kg. The concentrations were higher in the two subjects with a higher exposure of longer duration, as compared to the concentrations in the recently employed subject, who was exposed to lower concentrations in inspiratory air. Both of the two former subjects had a considerable estimated amount of body fat (27 and 41 kg). The calculated half-life of the concentration of styrene in adipose tissue after the end of exposure was 5.2 and 2.8 d for these two subjects. Therefore an elimination time of about five weeks is needed by the subject with the slowest elimination before the limit of detection (0.1 mg/kg) is reached.

“…The mandelic acid concentration (mean of 5 measurements) of the subjects with abnormal EEGs was higher (median 975 mg/dm 3 ) …”

Section: Neurophysiological Methodsmentioning

confidence: 99%

Neurophysiological findings among workers occupationally exposed to styrene.

Seppäläinen¹,

Härkönen²

1976

Self Cite

findings among workers occupationally exposed to styrene. Scand. j. work environ. & heaUh 3: (1976) 140-146. Ninety-six male workers oc'cupationally exposed to styrene in 24 plants producing reinforced polyester plastic products were studied neurophysiologically. The mean age of the subjects was 29.6 ± 7.4 years, and the duration of the exposure varied from 6 months to 14 years (mean 5.0 years). Mandelic acid concentration in the urine (mean of five values determined during five consecutive weeks) was used as the measure of exposure. The individual means of the mandelic acid concentrations varied from 7 to 4,715 mg/dm 3 (median 808 mg/dm 3 ). Neurotoxic effects of styrene exposure upon the central nervous system were revealed by abnormalities in the EEG. The overall prevalence of abnormal EEGs was· 24 Ofo (23 out of 96), which is higher than that found among a normal population (p < 0.05). Abnormal EEGs were found in one-third of the subjects with relevant styrene exposure (mandelic acid concentration over 700 mg/dm 3 ), while low-level styrene exposure did not increase the prevalence of normal EEGs above that found in a normal population. Nerve conduction velocity measurements performed on 40 subjects did not reveal any definite relationship between neuropathy and styrene exposure. The EEG examination is useful in the investigation of the neurotoxic effects of styrene. Whenever a possibility exists of excessive styrene exposure or beginning poisoning, the workers should be submitted to an EEG examination.