Urinary biomarkers of exposure to glycol ethers and chlorinated solvents during pregnancy: determinants of exposure and comparison with indirect methods of exposure assessment.

OBJECTIVES: To describe urine levels of metabolites of glycol ethers and chlorinated solvents in a sample of pregnant women from the general population, to study their occupational and non-occupational determinants and to compare them with the results of indirect assessment methods of solvent exposure. METHODS: A sample of 451 pregnant women was randomly selected from a general population cohort. At inclusion, the women in this sample completed a self-administered questionnaire about their social and medical characteristics, occupation and exposure to different products at work and in non-occupational activities. Occupational exposure to solvents was assessed from the woman's self-report and from a job-exposure matrix. Eight alkoxycarboxylic acids and trichloroacetic acid and trichloroethanol were measured with chromatography in urine samples collected at inclusion. Associations between metabolite levels and job titles, exposure to products used at work, and solvent exposure were studied. RESULTS: The different glycol ether metabolites were detected in 5.3%-96.4% of the urine samples, trichloroacetic acid in 6.4% and trichloroethanol in 5.5%. Nurses had butoxyacetic acid and phenoxyacetic acid in their urine most often, whereas methoxyethoxyacetic acid was the most frequent among nursing aides. Among cleaners, ethoxyacetic acid and ethoxyethoxyacetic acid were the most frequent. The occupation of hairdresser was associated with urinary excretion of ethoxyacetic acid, ethoxyethoxyacetic acid, butoxyacetic acid and phenoxyacetic acid. Among the women classified as exposed to solvents, the agents identified most often were ethoxyacetic acid, ethoxy-ethoxyacetic acid, butoxyacetic acid, phenoxyacetic acid, trichloroacetic acid and trichloroethanol. Ethoxyethoxyacetic acid was the only metabolite associated with non-occupational exposure. CONCLUSIONS: Metabolites of glycol ethers and chlorinated solvents were present at low levels in the urine of pregnant women. Most metabolites were associated with occupational exposure.

Selective screening for organic acidemias by urine organic acid GC-MS analysis in Brazil: fifteen-year experience.

BACKGROUND: The gas chromatography/mass spectrometry (GC/MS) method for organic acid analysis was established in developed countries since 1980s, but due to the small number of experienced clinical biochemists in this field and also the short availability of mass spectrometers scarce reports exist on the prevalence of organic acidemias (OAs) in developing countries like Brazil. METHODS: During January 1994 to July 2008, we analyzed organic acids by GC/MS in urine specimens obtained from Brazilian children with clinical suspicion of metabolic diseases. RESULTS: Two hundred and thirty four cases of disorders of organic acid metabolism, including 218 OAs (3.17%), were diagnosed among 6866 patients investigated. The most frequent disorders were primary lactic acidemia (57), methylmalonic acidemia (34), glutaric acidemia type I (33), propionic acidemia (18), 3-hydroxy-3-methylglutaric aciduria (17), L-2-hydroxyglutaric aciduria (9) and multiple carboxylase deficiency (9). Fourteen cases of mitochondrial fatty acid oxidation disorders, as well as 12 aminoacidopathies and 4 cases of vitamin B12 deficiency were also detected. Prompt treatment following diagnosis led to a better outcome in a considerable number of patients. CONCLUSION: Detection of OAs in loco in developing countries is important despite the implied extra costs, since it allows rapid therapy in many cases with a significant reduction of morbidity and mortality and makes the physicians more aware of these pathologies.

Quality assessment of urinary organic acid analysis.

The number of known inherited metabolic disorders resulting in an organic aciduria has increased steadily over the past two decades. Prompt and reliable detection is both clinically and technically demanding but is essential if appropriate treatment is to be undertaken. This is the first study of laboratory performance in the detection of these disorders to be undertaken in the UK. Some conditions were accurately identified by most laboratories: for example for maple syrup urine disease, 12 of 14 laboratories provided an appropriate response and medium chain acyl-CoA dehydrogenase deficiency was correctly identified by 15 of 17 laboratories. However, accuracy of detection was poorer for other conditions: for example, only eight of 17 laboratories detected tyrosinaemia type 1 and nine of 18 laboratories detected 4-hydroxybutyric aciduria. The strongest correlation with good performance was obtained by comparison with the extent of peak identification: r = 0.62, P = 0.002. The need for regular attendance at scientific symposia was also supported by a weaker positive correlation with the average score achieved, P = 0.08. Evidence also suggested that some of the laboratories with a low workload performed less well. No significant difference in performance could be demonstrated between the 17 laboratories who used gas chromatography-mass spectrometry and the six participants who used gas chromatography alone.

Assessment of exposure to organophosphate insecticides during spraying in Haiti: monitoring of urinary metabolites and blood cholinesterase levels.

Measurement of blood cholinesterase activity and of the urinary metabolites of fenitrothion (p-nitrocresol) and malathion (monocarboxylic acid) was used to assess the exposure to these insecticides of workers in the Haitian malaria control programme and of residents in the sprayed houses. Cholinesterase activity was significantly reduced at the end of the working week in 3 out of 28 fenitrothion workers. Urinary levels of p-nitrocresol (PNC) in the spraymen ranged from 2.2 to 25.2 mg/l. In fenitrothion workers who had no direct contact with spraying (weighers and supervisors), the cholinesterase activity remained >/= 75% of the normal control value, and the urinary PNC levels were relatively low. Urinary malathion monocarboxylic acid (MCA) levels at the end of the working week ranged between 1.1 and 5.3 mg/l in workers using malathion and their blood cholinesterase activity remained essentially normal. In both groups of workers the cholinesterase levels improved and the urinary excretion of metabolites decreased after 2 days of rest from the spraying operations. In the residents of the sprayed houses, low concentrations of PNC and MCA were detected in the urine 1 day after spraying and measurable but reduced levels were still present after 7 days. In all these cases the cholinesterase activity remained >/= 75% of the normal control value.