Difference between revisions of "Styrene"

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Styrene is considered the phenylalanine-glucose counterpart of [http://www.waiwiki.org/index.php/Acrylamide 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[http://www.ncbi.nlm.nih.gov/pubmed/15315399]. 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] Phenylalanine heated together with 1-hydroxyacetone or methylglyoxal yielded only 0.03 mol% styrene.[http://www.ncbi.nlm.nih.gov/pubmed/19680933]
 
  
Styrene is a polycyclic aromatic hydrocarbon (PAH), formed during incomplete combustion of organic compounds (as in cigarette smoke[http://www.ncbi.nlm.nih.gov/pubmed/10781869]) and a Maillard reaction product (and used in dyes). Similar to toluene and ethylbenzene, syrene is also released during food decaying processes[http://www.ncbi.nlm.nih.gov/pubmed/21541778] (as in spoiled salmon[http://www.ncbi.nlm.nih.gov/pubmed/17061824]). 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 a polycyclic aromatic hydrocarbon (PAH), formed during incomplete combustion of organic compounds (as in cigarette smoke[http://www.ncbi.nlm.nih.gov/pubmed/10781869]) and a Maillard reaction product (and used in dyes).
  
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=Formation==
 +
Styrene is considered the phenylalanine-glucose counterpart of [http://www.waiwiki.org/index.php/Acrylamide 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[http://www.ncbi.nlm.nih.gov/pubmed/15315399]. Phenylalanine heated together with 1-hydroxyacetone or methylglyoxal yielded only 0.03 mol% styrene.[http://www.ncbi.nlm.nih.gov/pubmed/19680933]
 +
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==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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==Migration from disposables==
 
Similar to 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] 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], 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]
 
Similar to 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] 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], 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]
  
olives and olive oil may also contain styrene[http://www.ncbi.nlm.nih.gov/pubmed/21111151], due to the uptake of aromatics, metabolized into styrene.[http://www.ncbi.nlm.nih.gov/pubmed/7785357] Blue-cheese fungi (eg Gorgonzola, camembert[http://www.ncbi.nlm.nih.gov/pubmed/17291386]) also produce styrene, as well as the plastics used for packaging.[http://www.ncbi.nlm.nih.gov/pubmed/20461461] Due to gram-negative bacteria in dairy, all raw milk cheeses also contain styrene (and o-dichlorobenzene; a derivative of benzene).[http://www.ncbi.nlm.nih.gov/pubmed/16013377] Cinnamon constituents naturally contain the styrene structure (incl. cinnamic acid[http://www.ncbi.nlm.nih.gov/pubmed/17360064]), which may get released due to the activity of fungal species present on cinnamon.[http://www.ncbi.nlm.nih.gov/pubmed/19723212] Total daily styrene exposure is estimated at maximally 0.17 mcg/kg bw[http://www.ncbi.nlm.nih.gov/pubmed/17364922] and human lifetime risk for tumors is estimated to be very low.[http://www.ncbi.nlm.nih.gov/pubmed/11738266] 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).[http://www.ncbi.nlm.nih.gov/pubmed/10781869]
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==Naturally produced==
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Similar to toluene and ethylbenzene, syrene is also released during food decaying processes[http://www.ncbi.nlm.nih.gov/pubmed/21541778] (as in spoiled salmon[http://www.ncbi.nlm.nih.gov/pubmed/17061824]).
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olives and olive oil may also contain styrene[http://www.ncbi.nlm.nih.gov/pubmed/21111151], due to the uptake of aromatics, metabolized into styrene.[http://www.ncbi.nlm.nih.gov/pubmed/7785357] Blue-cheese fungi (eg Gorgonzola, camembert[http://www.ncbi.nlm.nih.gov/pubmed/17291386]) also produce styrene, as well as the plastics used for packaging.[http://www.ncbi.nlm.nih.gov/pubmed/20461461] Due to gram-negative bacteria in dairy, all raw milk cheeses also contain styrene (and o-dichlorobenzene; a derivative of benzene).[http://www.ncbi.nlm.nih.gov/pubmed/16013377] Cinnamon constituents naturally contain the styrene structure (incl. cinnamic acid[http://www.ncbi.nlm.nih.gov/pubmed/17360064]), which may get released due to the activity of fungal species present on cinnamon.[http://www.ncbi.nlm.nih.gov/pubmed/19723212]  
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==Exposure==
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Total daily styrene exposure is estimated at maximally 0.17 mcg/kg bw[http://www.ncbi.nlm.nih.gov/pubmed/17364922] and human lifetime risk for tumors is estimated to be very low.[http://www.ncbi.nlm.nih.gov/pubmed/11738266] 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).[http://www.ncbi.nlm.nih.gov/pubmed/10781869]

Revision as of 19:24, 21 December 2012

Styrene is a polycyclic aromatic hydrocarbon (PAH), formed during incomplete combustion of organic compounds (as in cigarette smoke[1]) and a Maillard reaction product (and used in dyes).

Formation=

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], but hepatotoxicity (when metabolized to SO) in glutathione-depleted mice.[8] Environmentally, commercially manufactured polystyrene nanoparticles are taken up by algae and accumulate in fish, resulting in weight loss and altered cholesterol distribution[9], though may be eliminated within bile.[10] In rats, prenatal styrene exposure decreases postnatal serotonine and catecholamine levels in the brain.[11] Chronic exposure causes remodelling of the intestinal villi[12] and structural changes in apolipoproteins.[13] The testis may be the major target for styrene toxicity.[14] In rats, prenatal low level exposure to estrogenic styrene trimers obstructed genital organ development, and disrupted the endocrine systems of male rat offspring.[15]

Migration from disposables

Similar to bisphenol A and phthalates, plastic drink containers[16]] and plastic liners in cans and other polystyrene foam packages[17] are a source of styrene exposure from food/drinks. Except for polystyrene egg cartons, which leak no styrene into eggs.[18] 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.[19] Migration of styrene from disposable cups (styrofoam and PS, not paper cups) into drinks highly depends on fat content and temperature of drinks.[20] Butter[21], yoghurt[22][23], as the migration of styrene from packaging material very much depends on fat-contents of the liquid/food (and temperature).[24] 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.[25]

Naturally produced

Similar to toluene and ethylbenzene, syrene is also released during food decaying processes[26] (as in spoiled salmon[27]). olives and olive oil may also contain styrene[28], due to the uptake of aromatics, metabolized into styrene.[29] Blue-cheese fungi (eg Gorgonzola, camembert[30]) also produce styrene, as well as the plastics used for packaging.[31] Due to gram-negative bacteria in dairy, all raw milk cheeses also contain styrene (and o-dichlorobenzene; a derivative of benzene).[32] Cinnamon constituents naturally contain the styrene structure (incl. cinnamic acid[33]), which may get released due to the activity of fungal species present on cinnamon.[34]

Exposure

Total daily styrene exposure is estimated at maximally 0.17 mcg/kg bw[35] and human lifetime risk for tumors is estimated to be very low.[36] 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).[37]