Use In Consumer Products Research Articles

Pareto optimal metabolic engineering for the growth-coupled overproduction of sustainable chemicals.

Our research aims to help industrial biotechnology develop a sustainable economy using green technology based on microorganisms and synthetic biology through two case studies that improve metabolic capacity in yeast models Yarrowia lipolytica (Y. lipolytica) and Saccharomyces cerevisiae (S. cerevisiae). We aim to increase the production capacity of beta‐carotene (β‐carotene) and succinic acid, which are among the highest market demands due to their versatile use in numerous consumer products. We performed simulations to identify in silico ranking of strains based on multiple objectives: the growth rate of yeast microorganisms, the number of used chromosomes, and the production capability of β‐carotene (for Y. lipolytica) and succinate (for S. cerevisiae). Our multiobjective optimization methodology identified notable gene deletions by searching a vast solution space to highlight near‐optimal strains on Pareto Fronts, balancing the above‐cited three objectives. Moreover, preserving the metabolic constraints and the essential genes, this study produced robust results: seven significant strains of Y. lipolytica and seven strains of S. cerevisiae. We examined gene knockout to study the function of genes and pathways. In fact, by studying the frequently silenced genes, we found that when the GPH1 gene is knocked out in S. cerevisiae, the isocitrate lyase enzyme is activated, which converts the isocitrate into succinate. Our goals are to simplify and facilitate the in vitro processes. Hence, we present strains with the least possible number of knockout genes and solutions in which the genes are turned off on the same chromosome. Therefore, we present results where the constraints mentioned above are met, like the strains where only two genes are switched off and other strains where half of the knockout genes are on the same chromosome. This study offers solutions for developing an efficient in vitro mutagenesis for microorganisms and demonstrates the efficiency of multiobjective optimization in automatizing metabolic engineering processes.

Concentrations, distribution and potential health risks of organic ultraviolet absorbents in street dust from Tianjin, a megacity in northern China.

The distribution of organic ultraviolet absorbers (OUVAs) in outdoor dust remains poorly understood, especially in megacities. We measured the concentrations of 11 OUVAs in street dust from Tianjin, China, by a gas chromatography-mass spectrometry, and found total concentrations in the range of 10.3-129ng/g. These OUVAs were prevalent in the study street dust, but their concentrations were much lower than those in indoor dust reported in other areas previously. Benzophenone and octocrylene were the dominant OUVAs, representing medians of 15.5% and 13.1% of total OUVA concentrations, respectively. Total concentrations of dust OUVAs in the industrial area were higher than the residential, cultural and new urban areas. Source assessment indicated that the OUVAs likely originated mainly from the manufacture and consumption of cosmetics and personal care products, and some may have been from the production and use of OUVA-containing consumer products. The calculated non-carcinogenic risks of OUVAs in street dust were low. Our results further confirmed that the OUVAs were prevalent in the environment, provide useful information for understanding potential risks of these chemicals and developing risk management strategies. Further studies are needed to investigate the occurrence, environmental behaviors and potential risks of these emerging contaminants in outdoor environment.

Assessment of the Efficiency of Chemical and Thermochemical Depolymerization Methods for Lignin Valorization: Principal Component Analysis (PCA) Approach.

Energy demand and the use of commodity consumer products, such as chemicals, plastics, and transportation fuels, are growing nowadays. These products, which are mainly derived from fossil resources and contribute to environmental pollution and CO2 emissions, will be used up eventually. Therefore, a renewable inexhaustible energy source is required. Plant biomass resources can be used as a suitable alternative source due to their green, clean attributes and low carbon emissions. Lignin is a class of complex aromatic polymers. It is highly abundant and a major constituent in the structural cell walls of all higher vascular land plants. Lignin can be used as an alternative source for fine chemicals and raw material for biofuel production. There are many chemical processes that can be potentially utilized to increase the degradation rate of lignin into biofuels or value-added chemicals. In this study, two lignin degradation methods, CuO–NaOH oxidation and tetramethyl ammonium hydroxide (TMAH) thermochemolysis, will be addressed. Both methods showed a high capacity to produce a large molecular dataset, resulting in tedious and time-consuming data analysis. To overcome this issue, an unsupervised machine learning technique called principal component analysis (PCA) is implemented.

Characterizing and quantifying chemical ingredient use in consumer products between two separate databases and implications for environmental and human health exposure

Assessing chemical exposure in home and personal care products (HPCPs) represents an important data need. Key challenges to the assessment are related to limited knowledge in quantifying and characterizing the weight-fraction inclusion level and functionality of chemicals in HPCPs. Publicly available tools have been developed to address these challenges, such as the Chemical and Products database (CPDat). This study aims to evaluate the relative performance of CPDat by comparing estimates of weight-fraction inclusion level and functionality to other relevant data sources. Specifically, estimates obtained from CPDat are evaluated and compared with estimates obtained from marketing analytic data, using Euromonitor Passport for 31 commonly used chemicals found in HPCPs. The results obtained from this exercise suggest relatively good agreement between each of the methods for 10 chemicals (ρ = 0.92; P-value =0.02). When considering all 31 chemical ingredients, however, the correlation observed is generally poor (ρ = 0.46; P-value = 0.1), which is attributed to differences in how the underlying data are obtained for each method. With an emphasis on obtaining data based on mining datasheets for individual products, the application of CPDat is suggested to be useful for higher tiers of assessment, with data obtained from marketing analytics providing valuable input to exposure-based screening models. The insight gained from this study can be used to help guide the appropriate use of data obtained from different sources within a tiered exposure assessment.

Critical evaluation of ToxCast-Reactome predicted toxicity pathway correspondence of the human liver HepG2 activity profile with observed PFOA and PFOS hazards

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in the environment due to their persistence and widespread use in consumer products. The environmental fate and human health effects of two commercially successful PFAS, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), have been extensively studied. There is strong evidence that hepatotoxicity, immunotoxicity, and developmental toxicity observed in PFOA/PFOS-exposed rodents involve the activation of peroxisome proliferator-activated receptor-α (PPAR α); however, studies in PPAR α -null mice suggest that PPAR α -independent mechanisms also contribute to hepatotoxicity and immunotoxicity. During the prior decade, manufacturing uses of PFOA and PFOS were phased out as part of global stewardship programs; however, thousands of newer, less characterized PFAS are currently used as replacements. Consequently, there is a need for methods to efficiently identify the potential hazards of these alternative PFAS. This study critically evaluated an in silico hazard screening framework for PFAS focusing on PFOA and PFOS, whose toxicity has been well characterized. Data for human liver HepG2 cells were obtained from ToxCast to identify genes activated by PFOA or PFOS representing a primary target organ, and biological pathways were inferred using the Reactome database. Several biological pathways identified through the ToxCast-Reactome framework corresponded to potential human or animal hazards suggested in epidemiology or laboratory studies, increasing confidence in the proposed screening methodology. Thus, this in silico framework should be useful for assessing the hazard of the newer, less characterized PFAS, and may be adapted to other classes of toxicants as well.

Integration of data from the in vitro long-term exposure study on human endothelial cells and the in silico analysis: A case of dibutyl phthalate-induced vascular dysfunction

General population is exposed to dibutyl phthalate (DBP) through continuous use of various consumer products. DBP exhibits its effects mainly on the endocrine and reproductive system but it can also affect the function of the vasculature; however, the underlying mechanisms behind DBP-induced vascular dysfunction are not fully understood. To infer pathways, molecular functions, biological processes, and human diseases associated with DBP exposure, we integrated the toxicogenomic data obtained from the 4-week-long exposure of human vascular endothelial cells (ECs) to three environmentally relevant concentrations of DBP with the in silico analysis. Nine genes were affected by DBP exposure: six of the integrin family, VCAM1, ICAM1, and MMP2. As shown by the in silico analysis, changes in DBP-affected genes could affect extracellular matrix and binding of molecules and cells to ECs, thereby altering cell adhesion and migration. Several pathways, molecular functions, and biological processes were further identified to provide insight into the DBP-vascular disease relationships and the potential mechanism of action. The top three human disease categories associated with DBP exposure and vascular dysfunction include cardiovascular, cerebrovascular, and immune system diseases. Integration of experimental and in silico approaches may offer better understanding of the potential human health risks associated with DBP exposure.

Aquatic macrophytes mitigate the short-term negative effects of silver nanoparticles on denitrification and greenhouse gas emissions in riparian soils

Silver nanoparticles (AgNPs) are increasingly released into the aquatic environments because of their extensive use in consumer products and industrial applications. Some researchers have explored the toxicity of AgNPs to nitrogen (N) and carbon (C) cycles, but little is known about the role of aquatic plants in regulating the impact of AgNPs on these biogeochemical processes and related microorganisms. Here, two 90-day pot experiments were conducted to determine the effect of AgNPs on denitrification rates and greenhouse gas emissions in riparian wetland soils, with or without emergent plants (Typha minima Funck). As a comparison, the toxicity of equal concentration of AgNO3 was also determined. The results showed that AgNPs released a great quantity of free Ag+, most of which was accumulated in soils, while little (less than 2%) was absorbed by plant shoots and roots. Both AgNPs and AgNO3 could increase the soil redox potential and affect the growth and nutrient (N and phosphorus) uptake of plants. In soils with plants, there was no significant difference in denitrification rates and emissions of N2O and CH4 between control and AgNPs or AgNO3 treatments at all tested concentrations (0.5, 1 and 10 mg kg−1). However, low levels of AgNPs (0.5 mg kg−1) significantly enhanced CO2 emission throughout the experiment. Interestingly, in the absence of plants, a high dosage (10 mg kg−1) of AgNPs generally inhibited soil denitrification and stimulated the emissions of CO2, CH4 and N2O in the short-term. Meanwhile, the abundance of key denitrifying genes (nirS and nirK) was significantly increased by exposure to 10 mg kg−1 AgNPs or AgNO3. Our results suggest that emergent plants can alleviate the short-term negative effects of AgNPs on N and C cycling processes in wetland soils through different pathways.

Association between exposure to parabens and total mortality in US adults

BackgroundParabens are a group of endocrine disruptors that have been associated with health effects such as hypertension, diabetes, oxidative stress and obesity, which are associated with increased mortality risk over time. Women are exposed to higher paraben levels than men through use of consumer products. The current prospective study examines paraben exposure in association with mortality risk for women and men. MethodsWe analyzed 2005–2008 National Health and Nutrition Examination Survey (NHANES) data on urinary paraben analyte concentrations and covariates in adults aged 20 years and over, prospectively linked to National Center for Health Statistics (NCHS) mortality through 2015 (N = 2939). Proportional hazard regression models examined mortality risk in association with exposures, controlling for covariates for women and men. Covariates included age, race/ethnicity, smoking, education, income, body mass index, physical activity, self-reported health status and baseline health conditions. ResultsWomen were exposed to significantly higher concentrations of all studied parabens than men. Exposures were highest for methyl paraben. Women had significantly higher mortality risk in association with higher natural log exposure to ethyl (HR = 2.048, 95% CI 1.164–3.601), methyl (HR = 1.312, 95% CI 1.013–1.700), butyl (HR = 2.719, 95% CI 1.591–4.647) and total parabens (HR = 1.292, 95% CI 1.006–1.659). Exposure concentrations were associated with higher mortality risk for men only for ethyl paraben (HR = 2.532, 95% CI 1.217–5.268). DiscussionWomen were found to be at greater mortality risk in association with exposure to ethyl, methyl, butyl and total parabens. These findings require confirmatory research but add to the evidence base that exposure to parabens, probably through consumer products, may have adverse effects on human health, especially for women.

Consumer product use behavior throughout the product lifespan: A literature review and research agenda

Extending product lifespan has recently been recognized as an important strategy to achieve sustainable development. A substantial corpus of literature explores product lifespan from the perspective of product design or manufacturing practices, but the perspective of consumer has been largely overlooked. Addressing this void, this study systematically reviewed the literature on how consumer product use behavior influences the product lifespan. Insights gained from the review process guided our analysis on how product lifespan relates to consumer perceived value (comprising functional value, social value, and emotional value). We developed a five-stage framework to delineate the relationship between consumer perceived value and product use behavior across five-stages; namely, pre-acquisition, early use, middle use, late use, and pre-disposal. Furthermore, we identify promising directions for future scholarly work.

Engineering human liver fatty acid binding protein for detection of poly- and perfluoroalkyl substances.

Per- and polyfluoroalkyl substances (PFAS) are a large group of synthetic fluorinated chemicals with surface active and water-repellent properties. The combination of wide-spread use in numerous consumer and industrial products and extended biological half-lives arising from strong carbon-fluorine bonds has led to significant accumulation of PFAS in humans. As most human interaction with PFAS comes from ingestion, it is important to be able to detect PFAS in drinking water as well as in agricultural water. Here we present an approach to designing a fluorescence-based biosensor for the rapid detection of PFAS based on human liver fatty acid binding protein (hLFABP). Introduction of solvatochromic fluorophores within the ligand binding pocket (L50) allowed for intrinsic detection of perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and perfluorohexanesulfonic acid (PFHxS) via blue-shifts in fluorescence emission spectra. Initially, a single tryptophan mutation (L50W) was found to be able to detect PFOA with a limit of detection (LOD) of 2.8 ppm. We improved the sensitivity of the biosensor by exchanging tryptophan for the thiol reactive fluorophore, acrylodan. The acrylodan conjugated C69S/F50C hLFABP variant is capable of detecting PFOA, PFOS, and PFHxS in PBS with LODs of 112 ppb, 345 ppb, and 1.09 ppm, respectively. The protein-based sensor is also capable of detecting these contaminants at similar ranges in spiked environmental water samples, including samples containing an interfering anionic surfactant sodium dodecyl sulfate. Overall, this study demonstrates engineered hLFABP is a useful platform for detection of PFAS in environmental water samples and highlights its ease of use and versatility in field applications.

An Organic Laboratory Experience: Synthesis and Antimicrobial Screening of Brominated Parabens

A broadly applicable semester-long course-based undergraduate research experience (CURE)-inspired organic II laboratory course was developed from an engaging story supported by the current literature surrounding paraben use in consumer products. The project involves the synthesis of brominated parabens followed by an investigation into the structure–activity relationship between the ester lipophilicity and antimicrobial properties. The synthetic route for the project mirrors the sequence of reactions and topics typically covered in a second-semester organic course to support student learning within their lecture. The project culminates in a microbial cell death assay which lends a simple biological application to the project that is attainable for a broad audience of learners. The final assessments involve a notebook-based exam and the creation of an article mirroring a submission to the ACS journal Organic Letters. Three iterations of the course spread across three years and seven lab sections have supported the reliability of the synthetic route and have provided significant data validating the engaging nature of the lab course. Such engagement has decreased attrition, promoted better notebook skills, and helped to develop strong writing skills within our second-year undergraduates.

Firefighter exposures to potential endocrine disrupting chemicals measured by military-style silicone dog tags

Studies suggest that exposure to potential endocrine disrupting chemicals (pEDCs) may contribute to adverse health outcomes, but pEDC exposures among firefighters have not been fully characterized. Previously, we demonstrated the military-style silicone dog tag as a personal passive sampling device for assessing polycyclic aromatic hydrocarbon exposures among structural firefighters. This follow-up analysis examined the pEDC exposures based on department call volume, duty shift, and questionnaire variables. Structural firefighters (n = 56) were from one high and one low fire call volume department (Kansas City, MO metropolitan area) and wore separate dog tags while on- and off-duty (ndogtags = 110). The targeted 1530 analyte semi-quantitative screening method was conducted using gas chromatography mass spectrometry (npEDCs = 433). A total of 47 pEDCs were detected, and several less-frequently-detected pEDCs (<75%) were more commonly detected in off- compared to on-duty dog tags (conditional logistic regression). Of the 11 phthalates and fragrances detected most frequently (>75%), off-duty pEDC concentrations were strongly correlated (r = 0.31–0.82, p < 0.05), suggesting co-applications of phthalates and fragrances in consumer products. Questionnaire variables of “regular use of conventional cleaning products” and “fireplace in the home” were associated with select elevated pEDC concentrations by duty shift (paired t-test). This suggested researchers should include detailed questions about consumer product use and home environment when examining personal pEDC exposures.

Health effects associated with phthalate activity on nuclear receptors.

Phthalates are endocrine disruptors, widely used as plasticizers to impart flexibility in plastics, and as solvents in personal care products. Due to their nearly ubiquitous use in consumer products, most humans are exposed to phthalates daily. There has been extensive research on the reproductive health effects associated with phthalate exposure, but less attention has been paid to other actions. This review aims to summarize the known action of phthalates on different nuclear receptors. Some phthalates bind to and activate the estrogen receptor, making them weakly estrogenic. However, other phthalates antagonize androgen receptors. Some high molecular weight phthalates antagonize thyroid receptors, affecting metabolism. Several phthalates activate and interfere with the normal function of different peroxisome proliferator-activated receptors (PPARs), receptors that have critical roles in lipid metabolism and energy homeostasis. Some phthalates activate the aryl hydrocarbon receptor, which is critical for xenobiotic metabolism. Although phthalates have a short half-life in vivo, because people are continuously exposed, studies should examine the health effects of phthalates associated with long-term exposure. There is limited research on the effects of phthalates on health outcomes aside from reproductive function, particularly concerning are childhood adiposity, behavior, and learning. There is also limited information on actions of phthalates not mediated via nuclear receptors. Humans are exposed to multiple chemicals simultaneously, and how chemical mixtures act on nuclear receptor activity needs study. Although we know a great deal about phthalates, there is still much that remains uncertain. Future studies need to further examine their other potential health effects.

Cleaning product emissions and indoor built environments: Exposure and health risk assessments from experiments under realistic indoor conditions

Cleaning products are among the most widely used consumer products. The associated risks should be better understood. The health risk assessment (HRA) approach was applied to household uses of cleaning products, with nineteen products of various types and formats tested under typical indoor environmental parameters in an experimental house. The targeted substances included volatile organic compounds (VOCs) and carbonyl compounds. The generic “Common Use” and “Reasonable Worst-Case” scenarios under consideration were based on full cleaning sessions. These sessions were elaborated from data available in the technical and scientific literature, combined with stakeholder participation. The Common Use scenario included a 1 1/2-h cleaning session once per week, followed by manual ventilation; the Reasonable Worst-Case scenario included a 4-h session twice per week without manual ventilation. No situation of concern was found regarding chronic inhalation exposures associated with Common Use. For the Reasonable Worst-Case scenario, the assessed chronic inhalation risks were low. Assessed acute inhalation exposures (1-h exposures) could exceed the selected health values, mainly for acrolein (exposures up to 12 μg/m3) and formaldehyde (exposures up to ∼140 μg/m3). Associated first observed effects could include nasal, throat, and eye irritation. These results suggest that the highest exposures should be reduced and, to this end, that the emissions of the most emissive products should be reduced. Since the identified priority substances of concern are not specific to cleaning product emissions, multisource cumulative exposures are expected with the use of other consumer products, e.g., paints, incense, scented candles, furniture, and fragrance diffusers.

Application of new approach methodologies: ICE tools to support chemical evaluations

New approach methodologies (NAMs) for toxicological applications such as in vitro assays and in silico models generate data that can be useful for assessing potential health impacts of chemicals. The National Toxicology Program’s (NTP’s) Integrated Chemical Environment (ICE; https://ice.ntp.niehs.nih.gov/) provides user-friendly access to NAM data and tools to explore and contextualize chemical bioactivity and molecular properties. ICE contains curated in vivo and in vitro toxicity testing data and experimental physicochemical property data gathered from different literature sources. ICE also contains computationally generated toxicity data and physicochemical parameter predictions.ICE provides interactive computational tools that characterize, analyze, and predict bioactivity for user-defined chemicals. ICE Search allows users to select and merge data sets for lists of chemicals and mixtures, yielding summary-level information, curated reference data, and bioactivity details mapped to mechanistic targets and modes of action. With the Curve Surfer tool, the user can explore concentration–response relationships of curated high-throughput screening assays. The Physiologically Based Pharmacokinetics (PBPK) tool predicts tissue-level concentrations resulting from in vivo doses, while the In Vitro–In Vivo Extrapolation (IVIVE) tool translates in vitro activity concentrations to equivalent in vivo dose estimates. The Chemical Characterization tool displays distributions of physicochemical properties, bioactivity- and structure-based projections, and consumer product use information. Chemical Quest, the newest ICE tool, allows users to search for structurally similar chemicals to a target chemical or substructure from within the extensive ICE database. Retrieved information on target chemicals and those with similar structures can then be used to query other ICE tools and datasets, greatly expanding data available to address the user’s question. ICE links to other NTP and U.S. Environmental Protection Agency data sources, expanding ICE’s capacity to examine chemicals based on physicochemical properties, bioactivity, and product use categories.

Personal Passive Air Samplers for Chlorinated Gases Generated from the Use of Consumer Products.

Various chlorine-based disinfectants are being used during the COVID-19 pandemic; however, only a few studies on exposure to harmful gases resulting from the use of these disinfectants exist. Previously, we developed a personal passive air sampler (PPAS) to estimate the exposure level to chlorine gas while using chlorinated disinfectants. Herein, we investigated the color development of the passive sampler corresponding to chlorine exposure concentration and time, which allows the general population to easily estimate their gas exposure levels. The uptake and reaction rate of PPAS are also explained, and the maximum capacity of the sampler was determined as 1.8 mol of chlorine per unit volume (m3) of the passive sampler. Additionally, the effects of disinfectant types on the gas exposure level were successfully assessed using passive samplers deployed in a closed chamber. It is noteworthy that the same level of chlorine gas is generated from liquid household bleach regardless of dilution ratios, and we confirmed that the chlorine gas can diffuse out from a gel-type disinfectant. Considering that this PPAS reflects reactive gas removal, individual working patterns, and environmental conditions, this sampler can be successfully used to estimate personal exposure levels of chlorinated gases generated from disinfectants.

“Where do these chemicals come from?” Tracing-back chemical exposures to consumer products

BACKGROUND AND AIM: Non-targeted analysis has enabled us to screen biological samples for a broad spectrum of chemical compounds that would otherwise remain undetected with traditional targeted analytical techniques. While our previous studies have presented a number of man-made chemicals in human serum, the sources of many of these chemicals remain unknown. The aim of our study was to understand the sources of a group of chemicals, some of which are not actively biomonitored, (n=18; phenols, surfactants and per- and polyfluoroalkyl substances) identified and quantified in 300 maternal and 300 cord matched blood samples collected at delivery and analyzed with a non-targeted analysis workflow. METHODS: We matched measured concentrations in serum to questionnaire responses about participants’ use of consumer products in homes (n total = 148 questions) and evaluated their relationship using linear models. We also used an indoor environment multimedia fate model to test observed relationships by simulating concentrations of the chemicals in the carpets, furniture, dust and indoor air to evaluate the potential of exposure based on chemical mobility. RESULTS:We found strong positive correlations (r 0.5 and p-value 0.05) between concentrations in serum and carpets (installation and treatment), furniture (renovation and treatment), and floor (installation and treatment). One example where we measured widespread exposure in pregnant women is 4-nitrophenol. Our modeling calculations estimated that when 4-nitrophenol is emitted from carpets, it is expected to be resuspended and redeposited on vinyl floors and other surfaces leaving only a small fraction in the air available for inhalation (0.01 % of the total mass). Our modeling calculations also estimated that, due to its low volatility, the main route of exposure to 4-nitrophenol in the indoor environment is through dermal contact. CONCLUSIONS:Integrating non-targeted analysis with questionnaire data and multimedia modeling provided unique insights into the sources of environmental chemicals and pathways of exposure. KEYWORDS: exposome, non-targeted analysis, chemicals, exposure, modeling

Targeting the contribution of cosmetics brands to phthalate gestational exposure among Puerto Rican women in the PROTECT cohort

BACKGROUND AND AIM: Puerto Ricans are a highly exposed population to chemical substances from multiple sources, including personal care products. Our study, the Puerto Rico Testsite for Exploring Contamination Threats (PROTECT), has shown higher urinary phthalate levels among pregnant participants compared to women of reproductive age in the US. Pregnancy is a vulnerable time for the woman and the developing fetus. The contribution of cosmetics to phthalate levels has not been studied in Puerto Rico. Cultural context may influence access to healthier care products triggering an additional exposure burden for underrepresented populations. We examined urinary phthalate levels among PROTECT participants and frequency-specific cosmetic brand usage. METHODS: Use of personal care products was collected by interviewer-administered questionnaire at three separated times during pregnancy and phthalate urinary biomarkers were collected at the same time for a cohort of 1498 participants. Non-parametric (Mann-Whitney U Test and Kruskal Wallis Test) statistics were used to detect differences in median phthalate concentrations among groups and to detect differences among brands. Linear regression was used to compared phthalate levels by frequency of cosmetic usage. RESULTS:Overall, 78% of participants reported daily use of cosmetics, but usage declined from the first to the third visit. Daily users had higher levels of the metabolite mono-ethyl phthalate (MEP) compared to monthly, weekly, or no usage (p 0.05). For all three visits, the median concentration of MEP was higher in those participants that used cosmetics compared did not. From the 76 brands reported in our cohort, six brands were used by 63% of participants. Among that group, MEP concentrations varied by cosmetics brand and those differences were statistically significant. CONCLUSIONS:Cosmetic use during pregnancy is ubiquitous among PROTECT participants and their use appear to contribute to the phthalate burden during pregnancy. Results of this study could enhance risk assessments targeting pregnant women and consumer product use. KEYWORDS: Phthalates, Females, Exposures

Evaluation of enhanced darkfield microscopy and hyperspectral imaging for rapid screening of TiO2 and SiO2 nanoscale particles captured on filter media.

Here we report on initial efforts to evaluate enhanced darkfield microscopy (EDFM) and light scattering Vis-NIR hyperspectral imaging (HSI) as a rapid screening tool for the offline analysis of mixed cellulose ester (MCE) filter media used to collect airborne nanoparticulate from work environments. For this study, the materials of interest were nanoscale titanium dioxide (TiO2 ) and silicon dioxide (SiO2 ; silica), chosen for their frequent use in consumer products. TiO2 and SiO2 nanoscale particles (NPs) were collected on MCE filter media and were imaged and analyzed via EDFM-HSI. When visualized by EDFM, TiO2 and SiO2 NPs were readily apparent as bright spherical structures against a dark background. Moreover, TiO2 and SiO2 NPs were identified in hyperspectral images. EDFM-HSI images and data were compared to scanning transmission electron microscopy (STEM), a NIST-traceable technique for particle size analysis, and the current gold standard for offline analysis of filter media. As expected, STEM provided more accurate sizing and morphology data when compared to EDFM-HSI, but is not ideal for rapid screening of the presence of NPs of interest since it is a costly, low-throughput technique. In this study, we demonstrate the utility of EDFM-HSI in rapidly visualizing and identifying TiO2 and SiO2 NPs on MCE filters. This screening method may prove useful in expediting time-to-knowledge compared to electron microscopy. Future work will expand this evaluation to other industrially relevant NPs, other filter media types, and real-world filter samples from occupational exposure assessments.

Safer Sunscreens: Investigation of Naturally Derived UV Absorbers for Potential Use in Consumer Products

Safer Sunscreens: Investigation of Naturally Derived UV Absorbers for Potential Use in Consumer Products