Three-dimensional (3D) printing in tissue engineering and biosensing of analytes by using biocompatible materials or modifying surface structures is an upcoming area of study. This review discusses three common surface modification techniques, viz. alkaline hydrolysis, UV light photografting, and plasma treatment. Alkaline hydrolysis involves the reaction of an alkaline solution with the surface of a material, causing the surface to develop carboxyl and hydroxyl groups. This technique can enhance the biocompatibility, surface wettability, adhesion, printability, and dyeability of materials, such as acrylonitrile butadiene styrene (ABS), polycarbonate, and polylactic acid (PLA). This review also mentions details about some of the surface-modified 3D-printed diagnostic devices. Although most of the devices are modified using chemical processes, there are always multiple techniques involved while designing a diagnostic device. We have, therefore, mentioned some of the devices based on the materials used instead of categorising them as per modification techniques. 3D printing helps in the design of sophisticated shapes and structures using multiple materials. They can, therefore be used even in the design of microfluidic devices that are very useful for biosensing. We have also mentioned a few materials for printing microfluidic devices.

The water quality implications of transferring stormwater through pipes composed of concrete (new and used), polyvinyl chloride (PVC), galvanized corrugated steel (GCS), high-density polyethylene (HDPE), and pipes subjected to cured in place pipe (CIPP) and spray in place pipe (SIPP) trenchless repair technologies on stormwater quality are reviewed. Studies involve either the use of flowing water or an immersion experimental design, with data showing contact with pipe materials can affect stormwater quality parameters including pH, electrical conductivity (EC), and concentrations of minerals, metals, and organic constituents, e.g. styrene. \'In-transport\' changes in pH (1-3 units), EC (2-3-fold), bicarbonate (3-44-fold), and calcium (2-17-fold) in stormwaters were reported following exposure to concrete pipes. Differences between the use of synthetic and field-collected stormwater were identified, e.g. turbidity levels in field-collected stormwater reduced on passage through all pipe types, compared to synthetic water where levels of turbidity on exposure to concrete and cement-based SIPP increased slightly. Transfer through PVC and HDPE pipes had minimal effects on physicochemical parameters, whereas exposure to galvanized corrugated steel pipes led to increases in EC, Zn, and Pb. Though limited data was available, the use of CIPP repairs and associated waste condensate generated during thermal curing and/or incomplete curing of resins was identified to release organic contaminants of concerns (e.g. styrene, vinylic monomers, dibutyl phthalate (DBP), diethyl phthalate (DEP), and benzaldehyde). The implications of findings for both future research and stakeholders with responsibility for reducing diffuse pollution loads to receiving waters are considered.

Polymerization reactions have caused several severe accidents in the past since they are prone to runaways due to their highly exothermic and auto-accelerating nature. The heat generated during these uncontrolled runaway reactions surpasses the heat removal capacity of the cooling system leading to the auto-acceleration of the reactions. If proper measures are not taken to attenuate this auto-accelerative nature, dangerous consequences ensue, such as rampant boiling of the reaction system fluids or vapor production from secondary reactions. Both these consequences may eventually lead to over-pressurization followed by a thermal explosion. Thus, to eliminate the associated risk, polymerization reactions in industries are carried out in the presence of inhibitors which are injected into the reaction system before the initiation of polymerization. In this review, I have summarized various accidents that have happened in the past due to runaway polymerization implicating that there is an urgent necessity to do further research in this relatively less explored field of polymerization inhibition. To this end, I have completed an exhaustive survey of the various types of inhibitors used in industries and their inhibition mechanisms focusing mainly on the auto-initiated polymerization of styrene, methyl methacrylate, and acrylic acid monomer. Lastly, the synergism in the inhibition performance of a mixture of two types of inhibitors was also compared and discussed in detail.

Styrene is widely used in industrial applications. Inhalation exposure occurs in the industry. Some studies indicated that serum prolactin concentrations increased after exposure to styrene, while other studies found no change. In this systematic review, the search was done with the keywords styrene and prolactin in the PubMed, Science Direct, Web of Science and Scopus databases, regardless of the publication period. 118 studies were obtained and only seven articles were finally selected according to exclusion and inclusion criteria. The effect of styrene on prolactin secretion was selected in both human and animal studies. The increased response was seen in inhalation exposures. Subcutaneous exposure has no significant effect on prolactin levels. The observed responses were both dose-dependent and gender-dependent. Changes in serum prolactin were more frequent in women compared to exposed men. Dopamine depletion was not observed in all studies, so more tests on laboratory animals are necessary to clarify the possible mechanism.

The aim of introducing occupational exposure limits (OELs) is to use them as a risk management tool in order to protect workers\' health and well-being against harmful agents at the workplace. In this review we identify OELs for benzene, toluene, ethylbenzene, xylene (BTEX), and styrene concentrations in air and assess occupational exposure to these compounds through a systematic literature search of publications published in West Asian countries from 1980 to 2021. OELs for BTEX and styrene have been set in Iran and Turkey to levels similar to those in European countries and the US. The search yielded 49 full-text articles that cover studies of exposure assessment in six countries, but most (n=40) regard Iran. Average occupational exposure to benzene of workers in oil-related industries is higher than recommended OEL, while average occupational exposure to other compounds is lower than local OELs (where they exist). Currently, information about levels of occupational exposure to BTEX and styrene is insufficient in West Asian countries, which should be remedied through OEL regulation and application. Furthermore, coherent research is also needed to determine actual levels of occupational exposure, dose-responses, and the economic and technical capacity of local industries to address current issues.
Svrha je uvođenja graničnih vrijednosti profesionalne izloženosti (engl. occupational exposure limits, krat. OELs) upravljanje rizikom ne bi li se zaštitilo zdravlje i dobrobit radnika od štetnih agensa kojima su izloženi na radnome mjestu. U ovom smo pregledu izdvojili granične koncentracije benzena, toluena, etilbenzena, ksilena (BTEX) i stirena u zraku i, analizirajući 49 članaka objavljenih u zemljama (jugo) zapadne Azije od 1980. do 2021., pronađenih sustavnom pretragom literature, ocijenili profesionalnu izloženost tim spojevima. Granične vrijednosti za BTEX i stiren uvedene su samo u Iranu i Turskoj, i na sličnim su razinama kao one koje vrijede u europskim zemljama i SAD-u. Analiziranih 49 članaka obuhvaćaju istraživanja izloženosti u šest zemalja, ali se većina (njih 40) odnosi na Iran. Prosječna profesionalna izloženost benzenu u radnika u industrijama povezanima s naftom viša je od preporučene granične vrijednosti, a profesionalna izloženost ostalim spojevima niža je od lokalnih graničnih vrijednosti (tamo gdje su uvedene). Trenutačno nema dovoljno podataka o razinama profesionalne izloženosti BTEX-u i stirenu u zemljama (jugo)zapadne Azije, stoga je u njima potrebno regulirati granične vrijednosti i primjenjivati ih. Osim toga, potrebno je provoditi sustavna istraživanja ne bi li se utvrdile stvarne razine profesionalne izloženosti, odgovori na koncentracije onečišćivala i gospodarske i tehničke mogućnosti industrija tih zemalja da riješe trenutačne probleme.

We reviewed the toxicokinetics of styrene to introduce reliable surrogates for the biological monitoring of styrene workers. We have also discussed the extraction techniques and analytical methods of styrene and its metabolites. Sample preparation is the main bottleneck of the analytical techniques for styrene and its metabolites. Although some microextraction methods have been developed to overcome such disadvantages, some still have limitations such as long extraction time, fiber swelling and breakage, and the cost and the limited lifetime of the fiber. Among all, microextraction by packed sorbents, coupled with HPLC with ultraviolet detection (MEPS-HPLC-UV), can be the method of choice for determining styrene metabolites. Few studies investigated unchanged styrene in breath samples. Chemical determination of styrene in exhaled breath provides new insights into organ toxicity in workers with inhalation exposures and can be considered a fascinating tool in risk assessment strategies. Taking blood samples is invasive and less accepted by workers. In contrast, breath analysis is the most attractive method for workers because breath samples are easy to collect and non-invasive, and sample collection does not require the transfer of workers to health facilities. Therefore, developing selective and sensitive methods for determining styrene in breath samples is recommended for future studies.

The ingredients in food packaging migrate to the food inside. One of the most common compounds used for packaging of food is polystyrene. This systematic review aimed to investigate the level of styrene\'s pollution in food packed with polystyrene. The original articles include keywords styrene, polystyrene, food, contamination, pollution, \"food packaging\" were searched in Web of science, Medline, Scopus, and Science Direct. A total of 227 studies were achieved. The articles that did not meet the inclusion criteria were excluded with the initial evaluation. The quality assessment was conducted for full paper and finally data were extracted from 8 selected articles. Mata analysis, meta-regression, subgroup analysis, and publication bias was also conducted with comprehensive meta-analysis (CMA) software. Most of the examined samples were dairy products. The amount of fat in dairy products is an important factor in increasing the migration of styrene. The shelf life of product also had effect on migration of styrene. The overall average was estimated as 91.53 ± 26.18 µg/kg in food matrix. This amount is less than the permissible level. The results of meta regression showed that the type of food affects the pooled mean of styrene in the food. There was no publication bias for the selected articles.

Chromosome aberrations in the peripheral blood lymphocytes of styrene exposed workers have been suggested as a potential early marker for cancer risk. We performed a critical review and abstracted data from all studies using current chromosome aberration scoring criteria and providing at least a mean and standard deviation or standard error for the exposed and comparison groups. Using these data, we conducted a meta-analysis of occupational styrene exposed workers and incidence of chromosome aberrations. Our meta-analysis used the standardized mean difference as the summary statistic since all studies assess the same outcome but use different comparison populations. The primary meta-analysis of the 20 comparisons of 505 styrene exposed workers to 532 comparison workers found a meta-mean difference of 0.361 (95 % CI -0.084 to 0.807, random effects model), but there was substantial lack of consistency across studies (I2 of 90.11, p-value <0.001, fixed effect model). Studies with higher styrene exposures had lower mean standard differences compared to studies with lower styrene exposures. While studies of styrene workers overall had a slight increase in chromosomal aberrations relative to comparison groups, the lack of consistency across studies and the absence of an exposure response and other limitations of the reviewed studies including inadequate exposure assessment, small numbers of participants per study, and poorly matched exposed and comparison workers, we find insufficient evidence to support a conclusion that styrene exposure increases chromosome aberration frequencies in styrene workers.

Styrene is an important high production volume chemical used to manufacture polymeric products. In 2018, International Agency for Research on Cancer classified styrene as probably carcinogenic to humans; National Toxicology Program lists styrene as reasonably anticipated to be a human carcinogen. The genotoxicity literature for styrene and its primary metabolite, styrene 7,8-oxide (SO), begins in the 1970s. Organization of Economic Cooperation and Development (OECD) recently updated most genotoxicity test guidelines, making substantial new recommendations for assay conduct and data evaluation for the standard mutagenicity/clastogenicity assays. Thus, a critical review of the in vitro and in vivo rodent mutagenicity/clastogenicity studies for styrene and SO, based on the latest OECD recommendations, is timely. This critical review considered whether a study was optimally designed, conducted, and interpreted and provides a critical assessment of the evidence for the mutagenicity/clastogenicity of styrene/SO. Information on the ability of styrene/SO to induce other types of genotoxicity endpoints is summarized but not critically reviewed. We conclude that when styrene is metabolized to SO, it can form DNA adducts, and positive in vitro mutagenicity/clastogenicity results can be obtained. SO is mutagenic in bacteria and the in vitro mouse lymphoma gene mutation assay. No rodent in vivo mutation studies were identified. SO is clastogenic in cultured mammalian cells. Although the in vitro assays gave positive responses, styrene/SO is not clastogenic/aneugenic in vivo in rodents. In addition to providing updated information for styrene, this review demonstrates the application of the new OECD guidelines for chemicals with large genetic toxicology databases where published results may or may not be reliable. Environ. Mol. Mutagen. 2019. © 2019 Wiley Periodicals, Inc.

Previous epidemiology reviews of exposure to styrene and the risk of cancer considered studies published through 13 November 2013. Since then, additional relevant research has been published. No review has included meta-analyses. The current systematic review considered research published through June 2017; included meta-analyses of the relationship between any exposure to styrene and cancers identified as being of concern, including non-Hodgkin lymphoma (NHL), leukemia and cancers of the esophagus, pancreas, lung and kidney; and evaluated several other forms of cancer. Meta-relative risks for all studies were 1.14 (95% confidence interval (CI), 0.91-1.43) for NHL, 1.00 (95% CI, 0.80-1.26) for multiple myeloma, 0.98 (95% CI, 0.87-1.09) for all leukemia, 1.03 (95% CI, 0.92-1.15) for esophageal cancer, 1.02 (95% CI, 0.93-1.12) for pancreatic cancer, 1.09 (95% CI, 0.95-1.24) for lung cancer and 1.10 (95% CI, 0.99-1.22) for kidney cancer. Individual studies provided little evidence of exposure-response or induction time trends. Limitations of the available research and of the meta-analyses included reliance in most studies on mortality data rather than on incidence data, lack of quantitative estimates of styrene exposure for individual subjects and lack of information on lifestyle factors. Consideration of all pertinent data, including substantial recent research, indicates that the epidemiologic evidence on the potential carcinogenicity of styrene is inconclusive and does not establish that styrene causes any form of cancer in humans.