Difference between revisions of "Styrene"

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==Health effects==
 
==Health effects==
Styrene is metabolized / activated in the human body to phenylglyoxylic acid (alters dopamine levels)[http://www.ncbi.nlm.nih.gov/pubmed/9745934] or genotoxic styrene-7,8-oxide (SO).[http://www.ncbi.nlm.nih.gov/pubmed/11738266] SO is neurotoxic (synergistically with acrylamide).[http://www.ncbi.nlm.nih.gov/pubmed/8442002] Styrene is not carcinogenic[http://www.ncbi.nlm.nih.gov/pubmed/10048130], but hepatotoxicity (when metabolized to SO) in glutathione-depleted mice.[http://www.ncbi.nlm.nih.gov/pubmed/7712112] Environmentally, commercially manufactured polystyrene nanoparticles are taken up by algae and accumulate in fish, resulting in weight loss and altered cholesterol distribution[http://www.ncbi.nlm.nih.gov/pubmed/22384193], though may be eliminated within bile.[http://www.ncbi.nlm.nih.gov/pubmed/19799923] In rats, prenatal styrene exposure decreases postnatal serotonine and catecholamine levels in the brain.[http://www.ncbi.nlm.nih.gov/pubmed/11161651] Chronic exposure causes remodelling of the intestinal villi[http://www.ncbi.nlm.nih.gov/pubmed/22327877] and structural changes in apolipoproteins.[http://www.ncbi.nlm.nih.gov/pubmed/21978381] The testis may be the major target for styrene toxicity.[http://www.ncbi.nlm.nih.gov/pubmed/17120534] In rats, prenatal low level exposure to estrogenic styrene trimers obstructed genital organ development, and disrupted the endocrine systems of male rat offspring.[http://www.ncbi.nlm.nih.gov/pubmed/17259338]  
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Styrene is metabolized / activated in the human body to phenylglyoxylic acid (alters dopamine levels)[http://www.ncbi.nlm.nih.gov/pubmed/9745934] or genotoxic styrene-7,8-oxide (SO).[http://www.ncbi.nlm.nih.gov/pubmed/11738266] SO is neurotoxic (synergistically with acrylamide).[http://www.ncbi.nlm.nih.gov/pubmed/8442002] Styrene is not carcinogenic[http://www.ncbi.nlm.nih.gov/pubmed/10048130][http://www.ncbi.nlm.nih.gov/pubmed/7818769], but hepatotoxicity (when metabolized to SO) in glutathione-depleted mice.[http://www.ncbi.nlm.nih.gov/pubmed/7712112] Environmentally, commercially manufactured polystyrene nanoparticles are taken up by algae and accumulate in fish, resulting in weight loss and altered cholesterol distribution[http://www.ncbi.nlm.nih.gov/pubmed/22384193], though may be eliminated within bile.[http://www.ncbi.nlm.nih.gov/pubmed/19799923] In rats, prenatal styrene exposure decreases postnatal serotonine and catecholamine levels in the brain.[http://www.ncbi.nlm.nih.gov/pubmed/11161651] Chronic exposure causes remodelling of the intestinal villi[http://www.ncbi.nlm.nih.gov/pubmed/22327877] and structural changes in apolipoproteins.[http://www.ncbi.nlm.nih.gov/pubmed/21978381] The testis may be the major target for styrene toxicity.[http://www.ncbi.nlm.nih.gov/pubmed/17120534] In rats, prenatal low level exposure to estrogenic styrene trimers obstructed genital organ development, and disrupted the endocrine systems of male rat offspring.[http://www.ncbi.nlm.nih.gov/pubmed/17259338]
  
 
==Migration from disposables==
 
==Migration from disposables==

Revision as of 18:21, 22 December 2012

Styrene is a polycyclic aromatic hydrocarbon (PAH), formed during incomplete combustion of organic compounds (as in cigarette smoke[1]) and a (one of many) Maillard reaction product. Styrene polymeres are industrially produced for use in various products, including dyes and disposables.

Formation in cooked foods

Styrene is considered the phenylalanine-glucose counterpart of acrylamide (instead of asparagine-glucose). In the presence of sugars, phenylalanine, similarly to asparagine and lysine, can undergo carbonyl-assisted decarboxylative deamination reaction to generate styrene[2]. Phenylalanine heated together with 1-hydroxyacetone or methylglyoxal yielded only 0.03 mol% styrene.[3]

Health effects

Styrene is metabolized / activated in the human body to phenylglyoxylic acid (alters dopamine levels)[4] or genotoxic styrene-7,8-oxide (SO).[5] SO is neurotoxic (synergistically with acrylamide).[6] Styrene is not carcinogenic[7][8], but hepatotoxicity (when metabolized to SO) in glutathione-depleted mice.[9] Environmentally, commercially manufactured polystyrene nanoparticles are taken up by algae and accumulate in fish, resulting in weight loss and altered cholesterol distribution[10], though may be eliminated within bile.[11] In rats, prenatal styrene exposure decreases postnatal serotonine and catecholamine levels in the brain.[12] Chronic exposure causes remodelling of the intestinal villi[13] and structural changes in apolipoproteins.[14] The testis may be the major target for styrene toxicity.[15] In rats, prenatal low level exposure to estrogenic styrene trimers obstructed genital organ development, and disrupted the endocrine systems of male rat offspring.[16]

Migration from disposables

Similar to bisphenol A and phthalates, plastic drink containers[17]] and plastic liners in cans and other polystyrene foam packages[18] are a source of styrene exposure from food/drinks. Except for polystyrene egg cartons, which leak no styrene into eggs.[19] Bottled drinking water may contain styrene (up to 29.5 mcg/L; increased to 69.53 mcg/L after 1 yr storage) leached from the polystyrene (PS) bottle.[20] Migration of styrene from disposable cups (styrofoam and PS, not paper cups) into drinks highly depends on fat content and temperature of drinks.[21] Butter[22], yoghurt[23][24], as the migration of styrene from packaging material very much depends on fat-contents of the liquid/food (and temperature).[25] In the US, the exposure to styrene from polystyrene food-contact articles is estimated at 9 mcg per day, compared to 1 to 4 mcg /day for UK residents.[26]

Naturally produced

Similar to toluene and ethylbenzene, syrene is also released during food decaying processes[27] (as in spoiled salmon[28]). olives and olive oil may also contain styrene[29], due to the uptake of aromatics, metabolized into styrene.[30] Blue-cheese fungi (eg Gorgonzola, camembert[31]) also produce styrene, as well as the plastics used for packaging.[32] Due to gram-negative bacteria in dairy, all raw milk cheeses also contain styrene (and o-dichlorobenzene; a derivative of benzene).[33] Cinnamon constituents naturally contain the styrene structure (incl. cinnamic acid[34]), which may get released due to the activity of fungal species present on cinnamon.[35]

Human exposure

Total daily styrene exposure is estimated at maximally 0.17 mcg/kg bw[36] and human lifetime risk for tumors is estimated to be very low.[37] In another study the daily styrene exposure is estimated to range from 18.2 to 55.2 mcg per person (roughly 0.2 to 0.8 mcg/kg bw) with the greatest proportion coming from inhaled styrene (exhaust fumes, cigarette smoke, indoor heating).[38]