Introduction
Many toxic substances have been applied in the manufacture of equipment that is used to pack food, so as to give them their desired final characteristics. A possibility exists for these chemical substances to enter into food and cause problems in the human body. The increased use of chemicals with invention, has led to the utilization of more and more toxic substances in the plastic containers and the food industry in the United States. The risk of contamination of food and adulteration was detected, assessed and quantified in the past, by the use of gas and liquid chromatography, which were both invented in the United States in 1950s and 1960s (Lauren, 2009). Some of the chemical components that have been found as contaminants in the food industry include industrial chemicals like Benzene, heavy metals like mercury and lead, processing-produced toxins such as heterocyclic aromatic mines and acrylamides, and natural toxins. Food contamination through these and other substances has been projected to continue being a present and future problem, as a result of the global nature of food supply and advances in analytic capabilities. Therefore, these substances might have the potential of leaching from the plastic surfaces into foods and drinks contaminating them and possibly causing health problems.
This paper discusses the possibility of contamination of food by these chemical substances, and their impact on human body.
The topic of the contamination of food and water by migration of chemicals from plastic material and other products has generated a lot of debate on the global scale and consequently some countries have established provisions in the legislation regulating the use of plastics and other products in addition to sensitizing their citizenly on the possible effects of such contamination.
Plastic compounds contamination and exposure to humans and animals have been cited as one of the causes of many serious diseases and disorders being witnessed in nowadays health problems across the world. With the increased discovery of polymers and their applications man is now able to use the polymers for a wide range of applications. The process of making plastics commonly known as plasticization involves mixing a rigid thermoplastic with a low-molecular-weight substance known as the plasticizer in order to come up with a flexible material. Contamination from plastic products is mostly due to the used plasticizers. Such products that have been identified to have considerable contamination include, wall coverings, food containers, personal care products, medical products, and also in some solvents, lacquers, varnishes and coatings (Corea-Tellez, Bustamante-Montes, Hernandez-Valero, Vazquez- Moreno, n.d.).
Concern for Food Contamination
There exists enough evidence that food contamination has been a continuous problem over the past in the United States. This can be traced throughout the history of the Agricultural and Food Division (AGFD) and the formulated laws of the United States. The media, food processing companies and regulators in the food industry have been widely concerned over microbiological food safety issues in the United States. The government has already made approach in banning some products, requiring them not to be found as food components during testing.
Problem with Exposure to Food Contaminants
Food contaminants have widely been blamed for causing problems in the human body. These include allergy and asthma, among other health complications. This is because the food contaminants can be ingested into the body with the food, after migrating from the container (Maria & Hogg, 2007). The aforementioned authors recognize that food safety has included the monitoring of this migration. The chemicals may be included in food products via migration at different stages of the food chain. Included in the list of food contaminants are, of course, pesticide residues and food additives among others. Exposure assessment has played a key role in the generation of data that could aid in the sound judgment concerning risks to human health that relates to these contaminants (Maria & Hogg, 2007). In addition, the assessment also aids in the discovery of sources of contamination and their analysis, as well as providing important information necessary for strategizing for minimizing risks from chemical food contamination.
The human health risk with packaging materials as a result of exposure to the migrating substances is defined by the specific toxicity of the migrating substance, as well as the extent of this migration. The key characteristics that need to be considered during assessment are hazard characterization (the agent of contamination can provoke pathologies at certain levels of concentration), and exposure assessment. The latter involves the evaluation of the possibility to take in or ingest biological, chemical and physical agents through food and other sources of exposure (Maria & Hogg, 2007). It is important, in this evaluation, to mention the technical details of the substance or agent, describe the migration behavior, as well as provide the description for the methods of detection and/or quantification of the hazard in foods and packaging.
Hazard characterization involves the provision or description of the effects of health by different levels of the agent or hazard, the comprehensive profile of the substance and the possible degradation products. The nature of the packaging material also determines the contamination of food by the substances involved.
The understanding of the importance of the interaction of process of manufacture of the package and the package itself is very important. This is because sometimes, the techniques involved in the manufacture of packages require that food be processed in the packages. Different processing methods may have different impacts on the structural, mechanical and the barrier properties of the materials. The demand for better quality of food products, and safer ones, has led to the coming up of new techniques in the food industry, such as use of high-intensity electric fields, high-intensity pulsed light, irradiation and high pressure (Ozen & Floros, 2001). Treatment of foods in the package may be required in some of the processes like ozone treatment, irradiation and high pressure. Packages are also sometimes sterilized or disinfected by use of these techniques. Packaging achieves the protection of these foods from environmental conditions through protection of the food inside. Different types of materials to be used for packaging material depend on the mechanical and barrier properties of the packaging materials. The physical or chemical properties of the packaging materials may be altered by the processing conditions under which packaging is accomplished. Microwave as a process of food processing has been an area of study because of the possibility of migration of the “additives from the packaging materials used in microwave processing” (Ozen & Floros, 2001). Specifically, migration in microwaves is because of the high temperatures that are reached during cooking. The most used materials for the packaging products include Polyvinylidene Chloride (PVdC), Polypropylene (PP)/PET, and others. In order for the food to brown and crisp in the microwave, the susceptors-plastic film with a thin layer of aluminum or stainless steel deposited on the film-interact with the microwave radiation. Ranges of 0.02-2.73 ppm could be reached for PET oligomers migrating from materials such as susceptor pads and roasting bags. There are various factors that determine migration of the aforementioned components. These are nature of food surface, extent of contact with food, exposure time and the temperature attained during exposure. There has been reported migration of acetyl tributyl citrate (ATBC) and di (2-ethyl-hexyl) adipate (DEHA) from PVDC/PVC, as well as migration of antioxidants from high-density polyethylene (HDPE) and PP films. The latter has been tested on various components such as aqueous ethanol and corn oil (Ozen & Floros, 2001). Low-density polyethylene (LDPE) is the most widely utilized for food packaging products. The data required, and which is important in the analysis of migration of components from package into food, are packaging usage data, food consumption data, migration data and concentration of the substance in food. Some of the factors which are associated with migration include the surface area of the packaging material in contact with the foodstuff, the physical and chemical nature of migrants, and the time of exposure. The type of packaging material also dictates the migration, in that some (such as LDPE) have high diffusion coefficients than others (Silva, Cruz, Sendon, Franz, & Losada, 2009).
Leaching of Antimony from polyethylene terephthalate (PET) plastics have been evidenced in Europe and Canada. The chemical end-up in the drinking water contained in the plastic packaging bottles. The impacts, especially because antimony consumption has been associated with adverse health effects, maybe worse in places with high consumption of packaged drinking water, such as the southwestern US (Westerhoff, Panjai, Everett, & Alice, 2007). Moreover, the worldwide usage of bottled water in the world has increased by up to 91% in seven years according to Ceretti, Claudia, Ilaria, Licia, Mauro, Vanda, Francesco, Silvano, & Donatella (2009). The health impacts of Antimony in humans include diarrhea, vomiting and nausea, as well as decrease in blood sugar and increased blood cholesterol, on long exposure. The toxicity of both antimony and arsenic has been proved by research. The increase of usage of bottled water as compared to tap water, has arisen because of the associated convenience and safety perception (Westerhoff, Panjai, Everett, & Alice, 2007). 90% of the PET manufactured worldwide is produced in involvement of antimony-based catalysts because they are less expensive than the germanium-based catalysts. The characteristic of PET plastics being clearer, makes them be useable by industries and municipal water agencies. These clear plastics emphasize the “clean” nature of water, and therefore are more preferable by customers. There are other characteristics that make the bottles useful for the manufacture of bottles for storage of water. These include colorlessness, low weight, water vapor permeability, low gas, and resistance to chemicals. PET bottles are being favored to glass (Ceretti, Claudia, Ilaria, Licia, Mauro, Vanda, Francesco, Silvano, & Donatella (2009). PET degradation, which is determined by a number of storage conditions, causes water contamination where water containers are involved. However, there are components such as formaldehyde and acetaldehyde, which are carcinogenic or mutagenic in nature, which is released from PET bottles. There are various environmental factors that need to be understood, as they influence the release of antimony from the catalysts aforementioned, into water. The information on how Antimony catalysts may migrate from PET bottles and how it affects health may be useful in deciding a shift from usage of Antimony catalysts to germanium catalysts or to switch into using other types of plastics. Antimony leaching from PET bottles would be increased by increasing the storage temperature as evidenced in the experiment. These storage temperatures could be vehicles when people are traveling, garages, and other places. The experiment on the effects of pH on Antimony leaching provided evidence that pH had no effects on Antimony leaching. Results for the effects of outdoor sunlight on Antimony leaching were not statistically significant to prove that it had impact on the leaching (Westerhoff, et al., 2007). The aforementioned authors find that the type of bottle used could affect the leaching of Antimony from PET bottles. For example, experimental evidence proved that clear-colored PET plastics favored the release of Antimony from PET, four times more than blue-colored ones. There has been evidence of the presence of Sb (v)-citrate complex and a species identified as non-complex inorganic Sb(v) in citrus juices (Hansen & Spiros, 2006). It has been evidenced that a complex would result from the interaction of citrate present in the citrus fruit juices and Sb(v). Sb has a high affinity towards hydroxyl and carboxyl groups and citrate. Thus the findings providing evidence for a complex aforementioned are not surprising. Naturally occurring Sb-species may be converted into Sb-citrate or Sb-acetate complex. Storage conditions and the concentration of citrate in the samples were likely to affect the distribution of the Sb species in the juices (Hansen & Spiros, 2006). There has been evidence of trace amounts of acetaldehyde in PET bottles. The compound is also genotoxic in many biological systems (Ceretti, Claudia, Ilaria, Licia, Mauro, Vanda, Francesco, Silvano, & Donatella (2009). Presence of formaldehyde has also been evidenced in PET bottles. Formaldehyde has been witnessed as genotoxic and induces DNA and chromosomal damage in a wide range of organisms. The compound is also carcinogenic in nature. Research has evidenced the connection between some human health end-points (particularly genital development in infants) and the presence of urinary metabolites of phthalates. Production of liver tumors in rats and mice by one of the most commonly used phthalates (namely Di (2-ethylhexyl)phthalates-DEHP) has been evidenced by using a non-DNA reactive mechanism. Because the aforementioned mechanism is not likely relevant to humans, DEHP has not classified a human carcinogen. IARC has placed this component in Group 3. di-n-butyl phthalate (DBP) is another ester of phthalic acid, which has been termed by the National Toxicology Program (NTP) as one that could affect human reproduction and development. However, the exposure levels experienced by people have been lower than that leading to adverse effects in rodents (Ceretti, Claudia, Ilaria, Licia, Mauro, Vanda, Francesco, Silvano, & Donatella (2009).
Low molecular components present in synthetic polymers (which are usually of high molecular weights) present a health hazard to human beings. In addition, there are traces of unreacted monomers in these synthetic polymers, which pose a risk too. In general, additives, solvents, catalysts, starting substances, as well as monomers, possess the ability to migrate from plastic materials. Additives include dyes, plasticizers, antistatic among other components. Dry foods are usually wrapped with paper and pulp, which is composed of pulp originating from different vegetables. Present in paper and pulp as additives include grease-proofing agents, fluorescent whitening agents, sizing agents as well as starch, which together may constitute food contaminants and can be ingested together with the food.
Of course, the chemicals being associated with problems in the human body have been utilized to manufacture products and materials that are used in the food industry, and therefore they are directly connected. The utilization of these chemicals to manufacture products used in the food industry may be associated with benefits such as low cost of materials, availability, ease of use, among other benefits. Different chemical components and food contaminants have been found to cause different health complications. Polyvinyl Chloride (PVC) has been utilized for manufacture of covers for agricultural crops, food wrappers and other materials, and possesses the ability to migrate into the food substances. It has been specifically connected to allergy and asthma in the human body (Jaakkola & Knight, 2008). PVC has been termed as flexible and stable, and these characteristics make it suitable for use for materials in the food industry. The aforementioned characteristics are achieved with utilization of other plasticizers. Of the about 300 plasticizers discovered, about 50-100 are used commercially. The most utilized plasticizers have been found to be Phthalates, which are diesters of benzene dicarboxylic acid. There is wide usage of these components in the Western Europe, with about 1 million tones being produced yearly. According to Clark et al., (2003; cited in Jaakkola & Knight, 2008), Phthalates pose the ability, and indeed migrate from PVC-containing items into the air, dust, water, soil, e.t.c. and pollute the environment. The dangers of exposure to this chemical component have been evidenced through a study of human urine samples. Fatty food like oils and fish are the main sources of exposure to di-2-ethylhexyl phthalate (DEHP), being one of the most common diisononyl phthalate (DiNP). The other common type is dodecyl phthalate (DiDP). Medical procedures and consumer products have also been found as potential sources of contamination. Phthalates have been found to be present in indoor air and dust despite their volatility.
There are conditions that have been found to increase the likelihood of migration of Phthalates from PVC substances. Specifically, degradation of PVC flooring may be increased by dampness. High indoor concentration of a hydrolysis product of DEHP known as 2-ethyl-1-hexanol may result from the aforementioned. The avenues of exposure to Phthalates include ingestion, inhalation, dermal and parenteral although the proportional contribution of these sources is not clearly established (Jaakkola & Knight, 2008).
Factories have also been blamed for the contribution to the release of the food pollutants into the environment, and these pollutants either directly or indirectly find their way into food (Kira, Patricia, Magdalena, Maria, & Flavio, 2008). The factories mostly blamed here are those involved in the manufacture of plastic products such as wall and floor covering, containers among other products, as well as those factories dealing with plasticization.
Polymeric layers that coat food cans and tin containers have also been expressed as having the potential to cause health hazards. In addition, there are components that migrate from the metals forming the cans as well. There are lots of substances that are unknown, and which constitutes chemicals or substances that migrate from the coatings of food metal containers. In addition, there are those substances that are known. These are phenolic resins. Starting substances and their derivatives may also migrate from coatings used in these cans. Glazes and printing inks have been grouped into the category of substances that may migrate from glass food containers. There are several substances that are contained in glasses, which do not pose any danger. These include Sodium and Calcium oxides (Maria & Hogg, 2007).
There has arisen public concern and debates over the exposure to health hazards and problems as a result of Phthalates. In particular, Phthalates have affected immunological systems, airways, as well as causing carcinogenic and reproductive effects. However, evidence remains to be reviewed objectively (Jaakkola & Knight, 2008).
Compounds of Phthalates have been found to cause health problems. In particular, Phthalates esters have been found to cause effects in human reproductive systems. The toxic element that causes developmental effects and is present in the phthalate esters, is the monoester metabolite. Environmental exposures to phthalates have been associated with effects on “sperm and semen parameters in adults, anogenital distance in newborn males, as well as serum hormone levels in newborn infants” (Benson, 2008). The effects of the aforementioned chemicals include lack of adequate levels of testosterone, malfunctioning of the proper functioning of the Leydig cells. Malfunctions such as epididymis, vas deferens, decrease in anogenital distance, hypospadias, have been observed in rats. Reductions in mRNA and protein concentration were a likely effect of exposure to dibutyl phthalate. This was the case for proteins and enzymes that were utilized for the transportation of cholesterol and synthesis of testosterone. Several studies on exposure of various compounds associated with plastics have been centered on animals such as the rats. Diisobutyl phthalate possessed also the capability to cause adverse effects on developing male reproductive systems as would dibutyl phthalate.
Health effects of chemicals in plastic compounds
The compound BPA has been reported to cause adverse effects on female reproductive system and also in offspring in laboratory animals. In addition, bisphenol A is proposed to cause effects on the male reproductive tract. (Bredhult et al 2009). It has been established that BPA is a potential endocrine disrupter. (Cao, Corriveau and Popovic, 2009), the U.S Environmental Protection Agency established maximum daily dose that is tolerable for BPA as 50μg/kg. In Canada however, the tolerance is quite tight at 25μg/kg.
In a study to find out the effects of BPA it was concluded that it has a high possibility of affecting the mRNA expressions of genes that are involved in mitotic processes. The report on the study also indicates that increased BPA increases the rate of cell death. The inference of the study is that BPA has a significant influence on the female functions like endometrial angiogenesis which is important in the implantation of an embryo.
Bisphenol A is a component that has also been found to leak from plastic products and has health risks. The debate about them has also been controversial. The possible effects of exposure to the aforementioned chemical include the likelihood to act as the body’s hormone, leading to similar physiological effects on the body (Olivia, Bryant, Ramesh, Cesear, Jeffrey, & Charles, 2008). Carcinogenic effects such as breast cancer, among and other health problems or issues such as urethra malfunctioning, permanent change of genital tract, as well as development of obesity develop from exposure to the aforementioned chemical compound. Leaching of BPA from a solid polymer to a liquid face has been evidenced after the exposure of BPA-containing polymer products to heat or alkaline conditions. More specifically, babies who are bottle-feeding risk exposure to BPA through this activity. Environmental concentration of BPA may arise as a result of leaching out of the chemical from bottles at landfills.
There have however, rose arguments that BPA is not carcinogenic and does not affect reproduction and development in animals. There has also been a claim that human exposure to BP-derived polymers such as polycarbonates and epoxies can cause very minimal health risks (Ye & Kyu, 2009).
Migration of chemicals from plastic products
Some of the plasticizers used in manufacturing include dibutyl phthalate, diisobutyl phthalate, di(2- ethylhexyl) phthalate (DEHP) among others. It is reported that plasticizers like the DEHP can be released into the atmosphere through outdoor releases from plastic manufacturing factories, diffusion from plastic materials to the soil, and also water can get contaminated through groundwater contamination in waste disposal sites and landfills. It is reported that DEHP does not decompose easily and when traces are released to the atmosphere, its bond with dust and the compound formed is brought down on soil when it rains. Also contamination can result when consumer products like personal care products. However, the highest contributor of direct exposure of DEHP to humans is from flexible plastic tubing and blood and intravenous bags mostly used in health facilities. When these products are used in procedures like dialysis treatment, plastic coatings, blood transfusion among others they expose the patients to a higher risk of exposure to those chemical compounds.
Also other components with considerable contamination include Bisphenol A (BPA) which is used in making plastic linings of cans used in food and dental fillings. BPA is also available in some soft drinks and canned food products. However, the increased amount of this compound has been cited as due to their packaging coatings. This compound has been detected in biological samples such as follicular fluid, fetal serum and amniotic fluids. Also the compound has been detected in men and women’s polycystic ovary syndrome and in obese women. (Bredhult, Sahlin and Olovsson, 2009)
The migration of these chemical elements from the food packaging products and containers depends on many factors which include the chemical composition in the food, physical nature of the food in contact with the packaging, surface area of contact of food and the package, time and temperature of contact and finally the type of packaging material (Silva, Freire, Sendon, Frank and Loada 2009)
In a study to establish the difference in migration in different foodstuffs, it was established that migration of the chemical compounds on the packaging container to the foodstuff is negligible for honey and skimmed milk. It was also found out that there is considerable migration in dry foods and it was found to occur through fat and starch and also migration depends on the surface area in contact (Silva et al 2009).
Medical equipment made of Polyvinyl Chloride (PVC) are sometimes enhanced with DEHP mentioned earlier in this paper to impart flexibility and durability. However, DEHP has been found to produce reproductive and development toxicities in rodents and could contain possible negative effects on human beings. Urinary oxidative metabolites were visible in human urine, and these compounds are the products of metabolism of DEHP, through production of a metabolism intermediary product known as mono(2-ethylhexyl) phthalate (MEHP). The latter is excreted in the urine in the aforementioned metabolism products. The possibility of exposure of patients to DEHP has been estimated to occur above the normal population’s standard because medical equipment is, firstly made of DEHP, and secondly, this DEHP is not bound to the PVC. The patients’ categories that could undergo such exposure include those under blood transfusions, peritoneal dialysis, parental nutrition support, among others. Experimental, wide range of exposure to DEHP concentrations has been found to cause alteration of the reproductive system, birth defects, liver damage and cancer (Kavlock, et al., 2002; Gray, et al., 2003; ATSDR, 2002). This is so especially for male animals (Manori, Ella, James, Larry & Antonia, 2006). The consequences of experimental exposure of animals to the chemicals of concern here, include alteration of the reproductive system. The possible sources of exposure to DEHP could be either through ingestion or inhalation, the latter being facilitated by the availability of DEHP in the environment. The presence of phthalic acid, as well as other components in human urine samples of patients exposed to large doses of DEHP through medical interventions, has been evidenced (Albro, 1986; Albro, et al., 1983).
There have been raised questions on the fact that H1N1 virus is able to spread more in some places more than others. Arsenic element has been linked to flu morbidity, i.e. Arsenic, which naturally occurs in drinking water, causes increase in the flue spread (McGovern, 2009). Reproductive abnormalities including altered development of the mammary glands, reproductive tract lesions, as well as early onset of sexual maturation, have been associated with prenatal and neonatal exposure (McGovern, 2009). The aforementioned effects have been witnessed with rodent studies. There is no exploitive information on the human health effects of BPA. Babies have also been victims of exposure by the fact that substances that are harmful, such as Bisphenol A (Xu-Liang, & Jeannette, 2008; Ackerman, Gregory, Wendy, John, William, & Timothy, n.d.) migrate from the bottles that they use and may harm them. The inclusion of BPA in baby bottles manufactures components used for feeding babies (Brede et al., 2003). Of concern in this field is the way the stakeholders in the children welfare may face the issue. The aforementioned author also outlines that BPA has been found in urine (human urine). This was after people sampled drank polycarbonate bottles for a week. The Center for the Evaluation of Risks to Human Reproduction has featured that exposure to BPA could also cause disruption in the endocrine system (Canwile, Henry, Laura, Daniel, Caterina, Jennifer, Xiaoyun, Antonio & Karin, 2009). There has been more evidence that exposure to polycarbonate plastics and epoxy resins, may cause BPA to be ingested into food and cause health problems. There are properties that have helped in the utilization of polycarbonates in the food and beverages industry. These include durability, heat resistant material, and lightweight.
There are factors that have been associated with increased or reduced rate of migration of BPA from packages or containers. These conditions include acidic and alkali solutions, and time of simulation or exposure. Although new polycarbonate bottles are also associated with leakage of BPA into food and drinks, old bottles are also to blame for such migration (Howdeshell et al., 2003; Nalgene Outdoor, 2008). However, high rates of migration have been witnessed in used bottles (Canwile, Henry, Laura, Daniel, Caterina, Jennifer, Xiaoyun, Antonio & Karin, 2009). Used animal cages of polycarbonate exhibit a high equal rate of migration of BPA as compared to new cages, all at room temperature.
Countering Migration
Although a wide range of debates has focused on migration and the effects of the migrating substances on human health, there has arisen some amount of interest in controlling migration. There are several attempts that have been progressed to reduce the plasticizers’ migration from flexible PVC to the environment. Some of the techniques have focused on the modification of surfaces of flexible PVC articles with peroxides, acrylates, azides and sulfides among other products. Gamma radiations treatments or plasma exposure, have also been utilized in the treatment of these surfaces to reduce migration. Additives are the main concerns of migration from plastic equipment. The number of additives used will depend on the characteristics desired in the article. Plasticizers migrate to the surface of an article because of thermodynamic properties. Migration may lead to deteriorated properties of articles, or pose further danger to health because such components may contaminate the plasma, serum or blood of the child (Navarro, Monica, Myriam, & Helmut, 2010).
In order to eliminate the migration of the additive component from the surface or article, it is required that there be a covalent linkage of the additive to the polymer chains. There is a possibility to modify chemically, the PVC by nucleophilic substitution. High degree of modification is achieved best by the use of aromatic para-substituted thiol compounds as the most appropriate compounds for this job. Radicals are deactivated in the process, when one uses the aforementioned thiol compounds (Navarro, Monica, Myriam, & Helmut, 2010). Heavy metal salts can be replaced by either aliphatic and aromatic thiol compounds as heat/color stabilizers. The idea of user of thiol compounds as internal plasticizers was put forward in 1985 (Michel, Mijangos, Martinez, & Millan, 1985). However, there are disadvantages associated with the use of aliphatic thiols in this respect. Aliphatic thiols have been found not to show the balance between nucleophilicity and basicity that is necessary to eliminate side reactions. The elimination of these side effects is important because it ensures that degradation is avoided, as well as ensures the attainment of high degrees of modification (Navarro, Monica, Myriam, & Helmut, 2010). Thiols have also been employed to destroy thermally structural defects (Ge, Culyba, Grinnell, Zestos, Starnes, 2007).
Conclusion
In conclusion, there are many possibilities through which food can be contaminated. Chemical contamination of food may occur when the food gets into contact with the environment, pollutant component in the package or any other means. Contamination of food and drinks through the container has been evidenced by research. Such contamination has caused concern among the stakeholders-who include the government public health officials, the hospitals, the water resources departments, as well as the public itself-since it has connection with the health of the people. The contamination of food and drinks from packages containing them, has specifically been identified as associated with poor health conditions, as these components are ingested into the body. Plastics are the most used in manufacture of packaging because of a number of advantages. They are cheaper, flexible, easily available and moldable, and they can be recycled in addition to being flexible. Plastics are indeed becoming too hard to face out of the market. However, they have been associated with adverse health effects, far from their advantages as compared to other materials used for packaging, such as metal containers. There is a wide range of types of plastics grouped into two. Among the types of plastics utilized for making containers is LDPE. This category also has a wide range of sub-types. Many elements or compounds are used to enhance the chemical, physical, and other characteristics of plastics used for making containers. These components include the dyes, piments, that possess the ability to migrate from the containers into the food and drinks packed inside. The additives are added to achieve the desired results for the package or container or to enhance the existing properties. The migration is affected and determined by a range of conditions. The migration may happen during food treatment or processing in the factory, for example where the food must be treated while in the containers. Some of these conditions (and also factors affecting migration) include the temperature of treatment of the food, the method of treatment of the food, the type of plastic container or package or the chemical composition, and the nature of contact between the food and the container. Complications that are associated with ingestion of the migrated substances include asthma and respiratory problems, allergy among others. Studies have not only focused on the different types of compounds that possess the ability to migrate from the packages, but also their overall effects on our bodies. Comprehensive research has evidenced the migration of these components into the food and water being contained inside. Some compounds also possess the likelihood of migrating into food and water. The study of migration of the compounds found in the packaging material is essential for determining the best methods to ensure health of individuals. In addition, the discovery of the effects of compounds studies may pave way for the finding of the best alternative to plastics as packaging materials. The study of the migration and the effects of compounds found in plastics may aid in the determination of the best possible methods of avoiding danger and/or treatment of the conditions that arise from ingestion of the components. Because migration in metal containers has to do with the films in the coatings used, alternatives may also be found for the currently or mostly used materials.
Although there has been a long debate on migration of components from packages and containers, there have been significant efforts aimed at reducing or eliminating migration. Some of these have focused on the establishment of a covalent linkage between the substances such as the PVC, and the additives. This is through utilization of other additives. In addition, compounds such as the aromatic para-substituted thiol have been proposed for modification of substances (in this case PVC), to make it be able to form covalence bond with the additives. Although the aromatic para-substituted thiol compounds have been useful in this respect, side reactions have hampered positive results because they lead to lower levels of modification, as well as encouraging degradation. There is need to device a health policy that ensures that there are proper health standards maintained, which discourages migration (Erler, & Julie, 2009).
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