Abstract:In this study it is mainly focused on degradation of phthalates in beveragelevel containers and how to eliminate them after the contamination has beendone. Phthalate is very largely used (82 % of entire plasticizers) in polymerindustry as a plasticizer. There are lots of adverse effects of thoseplasticizers when they are in contact with human body such as reproductionsystem malfunctions and high cancer risks.
There have been differentexperiments to check different variables that are involving in degradationprocess. It is very important to remove leeched phthalates from water orbeverage to at least secure level to human body. This paper identifies theeffects on human body of phthalates, various experiences that have been done tocheck involvement of parameters in degradation process of phthalates andfinally studies on suitable removal methods.
Keywords:DEHP; Plasticizer; Degradation; Exposure; Cancer Risk; Removal Methods 1. IntroductionPlastics are hardand brittle without additives so it is essential to add those things topolymers. There is no chemical bond between phthalates and thePVC with which they have been mixed.
Consequently, they can evaporate or beleached out of the plastic and migrate to food. Thus they also enter thebody: through respiration, ingestion in food, and skin exposure. First ofall it is very important to identify what is the reason to emphasize thisresearch area.
The most active type of phthalate is DiEthyl Terephthalate(DEHP). It is known to have the highest concentrations in leeched samples. Sohere onwards the study is more focused on DEHP.Figure 1: Typical GC/MS chromatogramof PET bottle 2.
Adverse effects on human body ofphthalatesThere have been experienced a lot ofadverse effects on human body of phthalates.e.g., effects on endocrine balance and reproductive capacity and disruption ofthe immune and nervous systems. (“A variety of environmentally persistentchemicals, including some phthalate plasticizers, are weakly estrogenic.,” n.
d.) There are many researches which relevant to thetopic, more of them are based on the health impacts on exposure to thephthalates. A number of researchers have been tried to figure out the exactthreat to the living tissues but there is huge knowledge gap when it comes tohuman exposure.
In first case studyadult, regularly cycling Sprague-Dawley rats were used as test specimens. Inthis study they focused on female hormone levels after the exposure to DEHP andexposure resulted in prolonged estrous cycles and many anomalies in femalehormone levels which regard to reproduction. (Davis, Maronpot, & Heindel, 1994) . In next case study they used female LongEvans Rats to study the effects of the exposure to the Di-Ethylhexyl Phthalate(DEHP).
Mainly they focused on the effects on offspring of rats in this study.They observed a significant decrease in kidney and testes relative weight(organ/body weight) with a significant increase in relative liver weight afterthe exposure has been done. (Arcadi et al., 1998) .Since that high potential to attack the ovary DEHP may also be a reproductivetoxicant in women too. 3.
Contradictory findings that emphasize phthalatesare not harmful at all!In first one it is said that lead phthalates are notcarcinogen under any known condition. (Doull et al.,1999).The total weight-of evidence from mutagenicity studies clearly indicates thatDEHP is not genotoxic.
This conclusion is based on negative findings in a widerange of test systems to determine in vitro bacterial, yeast, insect,and mammalian cell mutagenesis, DNA interactions, and chromosomal aberrationsboth in vitro and in vivo.There have been studies to observe the expulsion ofphthalates after oral injection to human body. In contrast to previous studies,(Koch, Bolt,Preuss, & Angerer, 2005) most ofthe orally administered DEHP is systemically absorbed and excreted in urine.
Nodose dependency in metabolism and excretion was observed. Those are just main studies that were conducted on thesubject. People at risk for reproductive toxicity of DEHP are likely to includethose exposed occupationally as well as those exposed during medical proceduressuch as dialysis or blood transfusion. Of particular concern is DEHP exposurein newborns, who receive among the highest doses in the population from bloodtransfusions, extracorporeal membrane oxygenation, and respiratory therapy. (Tickner,Schettler, Guidotti, McCally, & Rossi, 2001).
Based on recent studies bythe CDC, exposure to phthalate esters is widespread and occurs at higher levelsthan previously anticipated. (Barr et al.,2003).4. Differentstudies to check involvements of parameters in degradation process ofphthalates There was a study to establishinvolvement to migration of phthalates with parameters like: type of phthalateused in the container, type of preservative used and the ph value of the sample. The analysis included 45 samplesof products packed in containers made from polyethylene terephthalate.
Thesamples were divided into 5 groups: group 1 (N=9), soft drinks preserved withorthophosphoric acid; group 2 (N=14), soft drinks preserved with Na-benzoate;group 3 (N=5), soft drinks preserved with K-sorbate; group 4 (N=8), soft drinkspreserved with a combination of Na-benzoate and K-sorbate; and group 5 (N=9),mineral water without preservatives.T he samples were analyzed by the method of gas chromatography.The highest rate of migration to soft drinks was recorded for dimethylphthalate, ranging from 53.51 to 92.
73 % that fact is also supported by theexperiment of (Keresztes, Tatár, Czégény,Záray, & Mihucz, 2013), whereas dibutyl phthalate anddiethylhexyl phthalate showed highest rate of migration to the mineral water(56.04 and 43.42 %, respectively). The highest level of phthalate migrationfrom plastic containers to soft drinks was found in the products preserved withK-sorbate. Definitely the phthalate leechability depended on the ph value of the sample.
With the lower ph values themigration levels were higher. Dimethyl phthalate showed highest migration topreserved drinks as an acidic medium. Almost inevery beverage or soft drink an acidic media is used to store the drink.(Embedded carbon di-oxide media which gives low PH value to the sample) (Bošnir et al., 2007) There were studies that were conducting using soda and vinegar and sameconclusion was drawn at that time. (Sax, 2010)When it comesto phthalate level in drinking water the maximum level of DEHP is 6.
0 ?g /l by US EPA (2009) standards. Most of the samples(80%) analysed are below that limit at purchase but after two weeks of storageat room temperature only 20% are below the regulation. Furthermore if we consider the limit of World Health Organisation(WHO), which is 8.0 ?g/l, all the water samples at purchase time were belowregulation for DEHP concentration.
Also he foundout there is effect on whether the polymer is virgin type or recycled polymer. Concentration of the phthalates is increased by time andtemperature. Here they used 3 conditions at purchase, water stored at fridge (40C) and water stored at room temperature (240C).
Even the samples arestored at low temperature it appears a slightly increasing in each compoundconcentration. In naturalmineral water samples growth rate of phthalates concentration is higher thanthe carbonated water samples. (“DETERMINATION OF PHTHALATESFROM BOTTLED WATER BY GC-MS – ProQuest,” n.
d.) Figure 2: Theeffect of storage temperature (22 °C, 40 °C, 50 °C and 60 °C) on DEHPconcentration for three different non-carbonated mineral water samples bottledin 0.5-L PET containers 5. Effect ofprolonged exposureThe result of this matter is quite way around and it hasshown that there is no relationship in this matter.
(Keresztes et al., 2013) found that there is no significant relationship betweenphthalate degradation and temperature in his research he used maximumtemperature of 60 0C. Figure 3: The effect of prolonged exposure time (24 h, 48h, 72 h) at 60 °C on the DEHP concentration for three different non-carbonated mineralwater samples bottled in 0.5-L PET containers. 6.
Effect on thestorage time of the sampleThe aging of the samples do have positive effect onphthalate migration to the samples. They could detect DEHP after 44 days ofstorage at 22 °C at traceable level. When it was stored over 1200 days theamount of DEHP level was remarkably high. (Keresztes et al., 2013) Figure 4: Evolution of phthalate concentration in non-carbonatedmineral water bottled in 2.0-L PET containers over time.
7. Effectof Surface Area/ VolumeThe rate of phthalate migration is also affected by thesurface/volume ratio. Higher ratios result higher migrations. Mineral waterpurchased in PET bottles of 0.5 L had the highest phthalate concentrationscompared to those obtained for waters of the identical brand bottled in 1.
5-L or2.0-L PET containers due to the higher surface/volume ratio.(Keresztes et al., 2013)Figure 5: The effect of contact surface area of 0.5-L,1.
5-L and 2.0-L PET bottles on the Phthalate concentration of non carbonatedmineral water. 8. Studieson using nano materials to remove leeched particlesThere are lot of studies thatsupport the fact that nano materials are efficient in removing contaminantsthat are considered as toxic added to the water. Those nano materials serve the purpose bydifferent mechanisms such as adsorption, desorption, oxidation, reduction,precipitation, dissociation and ion exchange.
(“Kineticsand thermodynamics of cadmium ion removal by adsorption onto nano zerovalentiron particles – ScienceDirect,” n.d.) Characteristics of nano particles such as pH of zero-pointcharge (Liang, Dai, Zhou, & Zhang,2014),adsorption properties like surface area and pore distribution (R, Me, Ms, & Ha, 2015), crystal structure andsize (Dave & Chopda, 2014) are important indetermining the removal efficiency of toxic constituents from water. Differentnano iron oxides (e.g. Titanium oxides, maghemite, goethite, Aluminium Oxides,hematite) have shown ability to remove toxic constituents by mechanisms ofadsorption and desorption (Hua, et al.
, 2012). In this study it was found that Tio2is capable of removing particles Zn, Cd, Pb, Ni like heavy metal ions. Nano sized ferric oxide has been reported tobe a low-cost adsorbent that can be used for removal of toxic metals in waterand secondary contamination of the ferric oxide is known to be negligible(Lee & Park, 2013). Nano sizedmanganese oxide has been shown high performance in sorption of cationic andanionic pollutants, arsenic and phosphate when present in water(Takamatshu, et al., 1989).Nano sized aluminumoxide has been reported as an excellent adsorbent for removing different heavymetals such as chromium, cadmium, lead, nickel, cobalt and manganese(Boparai & Joseph, 2013).
There are catalystgroups to sorption ability of Aluminium metal such as nitrate, phosphate, carboxylicand sulphate (Stietiya & Wang, 2014). Titanium oxide nanoparticles have been used for simultaneous removal of multiple heavy metals suchas Zinc, Lead, Cadmium, Nickel and Copper by adsorption (Hua, et al., 2012).
Photocatalyticproperties of nano titanium oxide have been attributed with advance oxidationcapacity for removal of toxic constituents from water (Lee & Park, 2013). Nano Zinc oxide hasbeen used as an effective adsorbent for removal of H2S, Copper andLead in water (Wang, et al., 2010). Nano magnesium particles have beenconsidered as a superior adsorbent for removal of heavy metals. Therefore,based on the findings of previous research, use of nano materials seem to be aprominent solution to remove toxic constituents that could be present in bothwater and beverages.
Development of a low-cost adsorbent using nano materialswill be a novel approach to provide safe products for industrial people andalso to general public.Titaniumdioxide is commercially available and easy to make by hydrolysis. 9. ConclusionWhenwe use phthalates as plasticizers to add polymers, different kinds of phthalatesleech out from polymer matrix to beverage product.
Even that degradationprocess happens under room temperature and atmospheric conditions. This leechout process is governed by many reasons. Even though there have been manystudies to check involvement in those factors some outcomes of thoseexperiments are confusing.
So that it is necessary to do proper research tocheck those confusing outcomes. When it comes to Sri Lankan beverage levelcontainers and PET water bottle industry there is necessity to find out ifdegradation level is within the allowable range. That becomes a critical matterwith reputation of low quality products in Sri Lanka. In addition to thatnowadays there is huge consumption of soft drinks and beverage products. Thoseleeched phthalates are certainly risk to health of population.
Like in abovematter even though there have been many researches on this matter results areconfusing. Actually there have not been experiments that were conducted onhuman subjects and also have been only very few studies on the matter. So it issafe to assume those phthalates are problematic to human health.Inremoving heavy metals from solutions it is clear nano materials are efficient,but there have not been enough experiments decide whether nano materials areeffective or not when it comes to phthalates. So purpose of this research is tocheck efficiency of Tio2 as nano material to remove phthalates fromdifferent beverages. 10.
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