- The text on this page is taken from an equivalent page of the IEHIAS-project.
APs are used as additives in plastics and as surface-active ingredients in industrial detergents and emulsifiers. Several APs such as nonylphenol (NP) are persistent, toxic, endocrine-disrupting chemicals.
Alkylphenols as biomarkers
Sample collection and storage
Human blood serum, cord blood serum and breast milk have been described as a suitable matrix for APs, though comparisons of AP levels in maternal blood and breast milk are missing so far.
- APs are ubiquitously present in food and are also detected in water and air samples
- Other routes of exposure include absorption through skin and inhalation or ingestion from pesticide sprays
- APs generally are rapidly metabolized
- In fish, biological half lives are estimated to be around 10-15 hours
Both blood and breast milk sampled can be gathered and stored using standard procedures. Samples are stored at -20°C
- Standard measurement methods include combinations of GC, LC, MS and HPLC techniques;
- ELISA methods have been developed for APs in the range of 5-500 ppb;
- Detection limit of LC/MS of<0.5 ng/ml serum;
- Detection limit of RP-HPLC with coulometric-array detection is 0.5-1 ng/ml.
- Reproducibility in breast milk is around 2.5-5% using GC/MS
- In blood samples, relative standard deviations of 10% are found using LC/MS
Analytical methods have been validated for a wide variety of matrices
No correlations between APs and confounding factors are so far described
Concentrations reported in literature:
- Nonylphenol in breast milk: 0.3 mg/kg
- NP in umbilical cord blood: N.D. – 15.17 ng/ml
- NP in blood serum: 0.58-16 ng/g serum (The Netherlands), 14-222 ng/g serum (Japan)
Dose-response relationships are observed in rats:
- Dose 0–60-90-120 mg/kg body weight: dose-response with uterine weight, expression of progesterone and estrogen receptors.
- Dose 0-50-100-200 mg/kg body weight: dose-response with testes and prostate weight, daily sperm production and sperm counts
Time trend, geographical variation, susceptibel groups:
No clearly defines groups with increased susceptibility, this may depend on exposure situations.