Alkylphenols
CATEGORY: Endocrine disruptor
USED IN: Hair products, spermicides, cleaning products and detergents, indoor air and dust
Alkylphenols are industrial chemicals used in the production of detergents and other cleaning products, and as antioxidants in products made from plastics and rubber. They are also found in personal care products, especially hair products, and as an active component in many spermicides. In the Silent Spring Institute study of household contaminants, alkylphenols—especially 4-nonylphenol (4-NP) and its breakdown products—were found in all samples of house air and 80 percent of house dust samples (Rudel, 2003). Substantial concentrations of these chemicals have also been found in wastewater associated with domestic sewers and municipal landfills (Slack, 2005; Swartz, 2006).
The alkylphenols, including 4-NP, have been shown to mimic the actions of estradiol, mediating their effects through the cellular estrogen receptor. They also bind to the newly described cell membrane ER and mimic cellular signaling responses usually controlled by estradiol (Thomas, 2006).
Prenatal exposure of rats to 4-NP causes altered development of the mammary gland as well as changes in steroid-receptor populations in several reproductive tissues (Moon, 2007). Treatment of mice with 4-NP led to an increased synthesis of estriol, a weak natural estrogen, by the livers of the treated animals. When compared with mice treated with equivalent amounts of estradiol, the mice exposed to 4-NP had an increased risk of mammary cancer (Acevedo, 2005).
In a study examining the effects of nonylphenol in human breast tumor cells (MCF-7) in vitro, changes in gene expression were observed in several genes involved in cell proliferation, DNA transcription and cell signaling—all systems that are disrupted in tumor formation (Oh, 2009).
