Free & total bisphenol A in urine of infants, hypospadias

[Guest guest]

Cite-2 provides perspective:

1. Determination of free and total bisphenol A in urine of infants.

<http://www.ncbi.nlm.nih.gov/pubmed/20970783>

Völkel W, Kiranoglu M, Fromme H.

Environ Res. 2010 Oct 21.

Infants may be particularly sensitive regarding hormonally active

compounds such as Bisphenol A (BPA), which is widely distributed and

exhibits weak oestrogenic activity. Since only free (unconjugated) BPA

exhibits endocrine activity, both free and total (after hydrolysis of

conjugates) BPA were determined in urine samples of infants to support

valid risk assessments. Free BPA was observed above the LOQ in only 3 of

91 (3%) samples from 47 infants. As total BPA was observed in only 38

(42%) urine samples, with concentrations between <LOQ and 17.85?g/l, the

median concentration was below the LOQ of 0.45?g/l. Based on 0.225?g/l

(half of the LOQ), a margin of exposure 1400-fold below the tolerable

daily intake (TDI) of 50?g/kgbw was calculated. The highest

concentration observed (17.85?g/l) was 18-fold below the TDI. Infants

who were fed using baby bottles show approximately 2-fold higher median

levels of total BPA. Importantly, the higher levels of total BPA

compared to free BPA demonstrate that conversion of BPA to biologically

inactive conjugates such as glucuronides or sulphates, which is well

known to efficiently occur in adults, also occurs in infants.

2. Parental occupational exposure to potential endocrine disrupting

chemicals and risk of hypospadias in infants.

<http://www.ncbi.nlm.nih.gov/pubmed/19939854>

Nassar N, Abeywardana P, Barker A, Bower C.

Occup Environ Med. 2010 Sep;67(9):585-9.

OBJECTIVES: Hypospadias is a urogenital birth defect affecting infant

boys. Periconceptual parental occupational exposure to endocrine

disrupting chemicals (EDCs) with oestrogenic or anti-androgenic

properties may adversely affect male genital development in utero. The

aim of this study was to investigate the association between both

maternal and paternal occupational exposures to EDCs and hypospadias.

METHODS: This registry-based case-control study considered 1202 cases of

hypospadias in children born in Western Australia between 1980 and 2000

and 2583 male controls randomly selected from birth records for whom

information regarding parental occupation was available from the Western

Australian Maternal and Child Health Research Database. Occupational

exposures to seven groups of potential EDCs were independently coded by

two researchers according to a validated job-exposure matrix.

*/

RESULTS/*: Multivariable analysis showed a strong association with

potential maternal occupational exposure to heavy metals with an over

twofold increased risk of hypospadias (OR 2.6; 95% CI 1.3 to 5.2), and

women exposed to phthalates were more likely to have an affected son (OR

1.2; 95% CI 0.8 to 1.7). Compared with mild or isolated cases, the risks

of moderate-severe hypospadias or multiple defects were increased up to

two- and fivefold, respectively, with maternal exposure to most types of

EDCs. Paternal occupational exposures to polychlorinated organic (OR

1.3; 95% CI 1.0 to 1.8) and bi-phenolic (OR 1.6; 95% CI 1.0 to 2.6)

compounds were also possible risk factors.

CONCLUSIONS: Our findings provide preliminary evidence of an association

between exposure to EDCs with oestrogenic or anti-androgenic properties

and increased risk of hypospadias.