Hairdressers' occupational exposure to carcinogenic aromatic amines

The hairdresser occupation is classified as probably carcinogenic to humans based on an excess risk for urinary bladder cancer, but it is unclear if current work as a hairdresser entails such a risk. The overall aim of this thesis was to investigate if hairdressers have an ongoing exposure to selected carcinogenic aromatic amines. We recruited 295 hairdressers, 32 consumers of hair dyes and 60 controls. All participants were non-smoking females, 18-55 years of age. Exposure over the past 4 months was determined for eight aromatic amines measured as haemoglobin (Hb) adducts. Hb adduct concentrations for hairdressers and consumers were not significantly higher than those of the controls for any of the eight aromatic amines. However, within the hairdresser group, ortho (o) and meta (m)-toluidine adduct concentrations tended to increase with the number of performed treatments with light-colour oxidative hair dyes. Furthermore, Hb adduct concentrations of o-toluidine increased significantly with the number of performed treatments of hair waving and m-toluidine adducts with the number of performed treatments with other oxidative hair dye. Professional hair products, mainly oxidative hair dyes, were collected from hairdressing salons and analysed for o-toluidine content. o-Toluidine was found in most of the analysed oxidative hair dyes but with a wide range in concentrations, even for the same colours. For semi-permanent (non-oxidative) hair dyes, oxidizing agents, hair waving products, and bleaching products, the content of o-toluidine was low or below limit of quantitation. To explore the effect of exposure to o- and m-toluidine among hairdressers, we determined telomere length and methylation of genes related to bladder or lung cancer. Hairdressers had a modest shortening of telomere length compared to non-hairdressers. No overall associations between telomere length and any of the Hb adducts were found, and no clear patterns between exposure as a hairdresser and hypermethylation of the selected genes. In conclusion hairdressers seem to have an ongoing occupational exposure to o- and m-toluidine as indicated by the associations with performed treatments with light-colour oxidative hair dye, other oxidative hair dye and hair waving. This is further supported by our finding of o-toluidine in most of the analysed oxidative hair dyes. However, no clear patterns were found between exposure as a hairdressers and hypermethylation of genes associated with bladder cancer and lung cancer. We observed a modest shortening of telomere length among the hairdressers, but the causality of the observation is uncertain since no overall exposure-response association was observed

Chronic exposure to cadmium and arsenic strongly influences concentrations of 8-oxo-7,8-dihydro-2'-deoxyguanosine in urine.

Exposure to arsenic (As), cadmium (Cd) and lead (Pb) may generate oxidative stress, which can be assessed by 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in urine, a sensitive marker of oxidatively damaged DNA. We have evaluated oxidative stress induced by mixed chronic exposure to As, Cd, Pb, as well as the influence of As metabolism and nutritional status, i.e. ferritin (Ft), selenium (Se), zinc (Zn), manganese (Mn) and body weight. 8-oxodG was measured in urine from 212 women in early pregnancy from Matlab, rural Bangladesh, using LC-MS/MS. Cd and Pb were analyzed in urine and erythrocytes, while Se, Mn and Zn were analyzed in erythrocytes, all by ICPMS. As and As metabolites were analyzed in urine by HPLC-ICPMS. Ferritin was analyzed in plasma by radioimmunoassay. Median concentration of 8-oxodG was 8.3 nmol/L (adjusted for specific gravity), range 1.2-43, corresponding to a median of 4.7 mug/g creatinine, range 1.8-32. 8-oxodG was positively associated with urinary Cd (ss=0.32, p<0.001), urinary As (ss=0.0007, p=0.001), fraction of the monomethylated arsenic metabolite (MMA) in urine (ss=0.0026, p=0.004) and plasma Ft (ss = 0.20, p<0.001). A joint effect was seen for U-Cd and U-As, but whether this effect was additive or multiplicative was difficult to discern

Alterations of telomere length and DNA methylation in hairdressers: A cross-sectional study.

Working as hairdressers has been associated with increased risk for cancer, particularly bladder cancer. To evaluate if current hairdressers have elevated risks of adverse health effects, we measured several biomarkers related to cancer-related DNA alterations. We enrolled 295 hairdressers and 92 non-hairdressers (all female non-smokers) from Stockholm and southern Sweden. Questionnaire data were collected for each participant, including work tasks for the hairdressers. We measured telomere length in peripheral blood leucocytes using quantitative PCR and DNA methylation status of genes relevant for bladder cancer using methylation sensitive high resolution melting analysis. The hairdressers had shorter telomeres (β = -0.069, P = 0.019) compared with non-hairdressers. Shorter telomeres were found in hairdressers up to 32 years old performing hair waving more than once per week as compared with hairdressers in the same age group performing hair waving less often (β = -0.12, P = 0.037). Hair waving was associated with less frequent CDKN2A methylation (odds ratio, OR = 0.19, P = 0.033). Shorter telomeres in hairdressers may indicate a genotoxic effect. Performing hair waving was associated with short telomere length, although the effect was only observed in young hairdressers. No clear patterns were discerned with regard to DNA methylation of bladder cancer-related genes. The observed changes of methylation were not all in the expected direction and warrant further investigation. Environ. Mol. Mutagen., 2015. © 2015 Wiley Periodicals, Inc

0253 Hairdressers are occupationally exposed to ortho- and meta- toluidine

Hairdressing work is classified as carcinogenic based on excess risk for bladder cancer. We aimed at evaluating if current hairdressers are exposed to established/suspected bladder carcinogens (aromatic amines) and indicate possible sources of exposure

Exposure of hairdressers to ortho- and meta-toluidine in hair dyes.

Carcinogenic aromatic amines derived from hair dyes have recently received new attention. One of these is ortho (o)-toluidine, which is classified as carcinogenic to humans