Difference between revisions of "Styrene"

From WaiWiki
(Migration from disposables)
(Migration from disposables)
Line 8: Line 8:
  
 
==Migration from disposables==
 
==Migration from disposables==
Similar to acrylonitrile[http://www.ncbi.nlm.nih.gov/pubmed/1999304], bisphenol A and phthalates, plastic drink containers[http://www.ncbi.nlm.nih.gov/pubmed/22043764]] and plastic liners in cans and other polystyrene foam packages[http://www.ncbi.nlm.nih.gov/pubmed/17164219] are a source of styrene exposure from food/drinks. Except for polystyrene egg cartons, which leak no styrene into eggs.[http://www.ncbi.nlm.nih.gov/pubmed/7797174] 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.[http://www.ncbi.nlm.nih.gov/pubmed/17915704] Migration of styrene from disposable cups (styrofoam and PS, not paper cups) into drinks highly depends on fat content and temperature of drinks.[http://www.ncbi.nlm.nih.gov/pubmed/19750020]  
+
Similar to acrylonitrile[http://www.ncbi.nlm.nih.gov/pubmed/1999304], benzene[http://www.ncbi.nlm.nih.gov/pubmed/2354739], bisphenol A and phthalates, plastic drink containers[http://www.ncbi.nlm.nih.gov/pubmed/22043764]] and plastic liners in cans and other polystyrene foam packages[http://www.ncbi.nlm.nih.gov/pubmed/17164219] are a source of styrene exposure from food/drinks. Except for polystyrene egg cartons, which leak no styrene into eggs.[http://www.ncbi.nlm.nih.gov/pubmed/7797174] 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.[http://www.ncbi.nlm.nih.gov/pubmed/17915704] Migration of styrene from disposable cups (styrofoam and PS, not paper cups) into drinks highly depends on fat content and temperature of drinks.[http://www.ncbi.nlm.nih.gov/pubmed/19750020]  
 
Up to 150 mg styrene /kg was transferred from polystyrene disposables into sunflower oil and up to 90 mg/kg into individual serving milk products.[http://www.ncbi.nlm.nih.gov/pubmed/8314394] Butter[http://www.ncbi.nlm.nih.gov/pubmed/17705437], yoghurt[http://www.ncbi.nlm.nih.gov/pubmed/17364921][http://www.ncbi.nlm.nih.gov/pubmed/9666894] may also contain styrene, as the migration of styrene from packaging material very much depends on fat-contents of the liquid/food (and temperature).[http://www.ncbi.nlm.nih.gov/pubmed/9829045] 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.[http://www.ncbi.nlm.nih.gov/pubmed/7480894]
 
Up to 150 mg styrene /kg was transferred from polystyrene disposables into sunflower oil and up to 90 mg/kg into individual serving milk products.[http://www.ncbi.nlm.nih.gov/pubmed/8314394] Butter[http://www.ncbi.nlm.nih.gov/pubmed/17705437], yoghurt[http://www.ncbi.nlm.nih.gov/pubmed/17364921][http://www.ncbi.nlm.nih.gov/pubmed/9666894] may also contain styrene, as the migration of styrene from packaging material very much depends on fat-contents of the liquid/food (and temperature).[http://www.ncbi.nlm.nih.gov/pubmed/9829045] 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.[http://www.ncbi.nlm.nih.gov/pubmed/7480894]
  

Revision as of 18:46, 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 acrylonitrile[17], benzene[18], bisphenol A and phthalates, plastic drink containers[19]] and plastic liners in cans and other polystyrene foam packages[20] are a source of styrene exposure from food/drinks. Except for polystyrene egg cartons, which leak no styrene into eggs.[21] 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.[22] Migration of styrene from disposable cups (styrofoam and PS, not paper cups) into drinks highly depends on fat content and temperature of drinks.[23] Up to 150 mg styrene /kg was transferred from polystyrene disposables into sunflower oil and up to 90 mg/kg into individual serving milk products.[24] Butter[25], yoghurt[26][27] may also contain styrene, as the migration of styrene from packaging material very much depends on fat-contents of the liquid/food (and temperature).[28] 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.[29]

Naturally produced

Similar to toluene and ethylbenzene, syrene is also released during food decaying processes[30] (as in spoiled salmon[31]). olives and olive oil may also contain styrene[32], due to the uptake of aromatics, metabolized into styrene.[33] Blue-cheese fungi (eg Gorgonzola, camembert[34]) also produce styrene, as well as the plastics used for packaging.[35] Due to gram-negative bacteria in dairy, all raw milk cheeses also contain styrene (and o-dichlorobenzene; a derivative of benzene).[36] Cinnamon constituents naturally contain the styrene structure (incl. cinnamic acid[37]), which may get released due to the activity of fungal species present on cinnamon.[38]

Human exposure

Total daily styrene exposure is estimated at maximally 0.17 mcg/kg bw[39] and human lifetime risk for tumors is estimated to be very low.[40] 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).[41] In Canada daily intakes of styrene for the general population were estimated at 0.004 to 0.17 mcg/kg bw from ambient air, 0.07 to 0.10 mcg/kg bw from indoor air and up to 0.58 mcg/kg from food. The estimated intakes from drinking-water and soil were negligible. Potential exposure from cigarette smoke (20 cigarettes / day) was estimated to be 2.86 mcg/kg bw per day.[42]