Temporal variability in urinary excretion of bisphenol A and seven other phenols in spot, morning, and 24-h urine samples

Relationship between urine dichlorophenol levels and asthma morbidity

BACKGROUND

Chlorinated phenols are associated with atopic conditions, but it is not known whether they are associated with wheeze or asthma and whether atopy is involved in these associations.

OBJECTIVES

To test the association between urine levels of 2 dichlorophenols (2,4- and 2,5-dichlorophenols) and asthma morbidity in atopic and nonatopic wheezers and between total serum immunoglobulin E (IgE) levels.

METHODS

Data from a sample of 2,125 participants at least 6 years old from the US National Health and Nutrition Examination Survey 2005 to 2006 were analyzed. Asthma morbidity data were available for those participants who reported wheezing in the past year ("wheezers"; n = 250). This subsample was categorized as atopic or nonatopic.

RESULTS

Atopic wheezers with higher 2,5-dichlorophenol levels were more frequently diagnosed with asthma by a physician (odds ratio [OR] 4.7 for highest vs lowest tertile, P < .001), required more prescriptions for asthma medications (OR 2.2, P = .046), and reported more exercise-induced wheezing (OR 5.8, P = .045) than atopic wheezers with low dichlorophenol levels. Atopic wheezers with higher 2,5- or 2,4-dichloropheonol levels also were more likely to miss work or school because of wheezing (OR 10.0, P < .001; OR 11.4, P < .01, respectively). In contrast, in nonatopic wheezers, there were no significant associations between dichlorophenol levels and asthma morbidity measurements. The 2 dichlorophenol metabolites were positively associated with increased serum IgE levels in the larger study sample.

CONCLUSION

These findings indicate that in patients with atopy and a history of wheezing, asthma morbidity is associated with high urinary dichlorophenol levels. Increased urine dichlorophenol levels are associated with higher total serum IgE.

Human urinary excretion of non-persistent environmental chemicals: an overview of Danish data collected between 2006 and 2012

Several non-persistent industrial chemicals have shown endocrine disrupting effects in animal studies and are suspected to be involved in human reproductive disorders. Among the non-persistent chemicals that have been discussed intensively during the past years are phthalates, bisphenol A (BPA), triclosan (TCS), and parabens because of their anti-androgenic and/or estrogenic effects. Phthalates are plasticizers used in numerous industrial products. Bisphenol A is the main component of polycarbonate plastics and epoxy resins. Parabens and TCS are antimicrobial preservatives and other phenols such as benzophenone-3 (BP-3) act as a UV-screener, while chlorophenols and phenyl phenols are used as pesticides and fungicides in agriculture. In spite of the widespread use of industrial chemicals, knowledge of exposure sources and human biomonitoring studies among different segments of the population is very limited. In Denmark, we have no survey programs for non-persistent environmental chemicals, unlike some countries such as the USA (NHANES) and Germany (GerES). However, we have analyzed the excretion of seven parabens, nine phenols, and the metabolites of eight different phthalates in urine samples collected over the past 6 years from four Danish cohorts. Here, we present biomonitoring data on more than 3600 Danish children, adolescents, young men, and pregnant women from the general population. Our study shows that nearly all Danes were exposed to the six most common phthalates, to BPA, TCS, and BP-3, and to at least two of the parabens. The exposure to other non-persistent chemicals was also widespread. Our data indicate decreasing excretion of two common phthalates (di-n-butyl phthalate and di-(2-ethylhexyl) phthalate) over time.