Multi-source exposure and health risks of phthalates among university students in Northeastern China

Safety of new food contact materials: Migration and sorption studies based on Tenax, powdered milk, baby cereal and oat flakes

This paper presents migration tests of environmental and production contaminants, migrating from food contact materials (FCMs) into Tenax. Migration tests were conducted under two time and temperature conditions (2 h, 70 °C, 10 days, 40 °C). Various chromatographic methods (GC/FID, GC/ECD, GC/MS, HPLC/DAD) were used to identify and quantify the migrants. The specific surface area and pore distribution of Tenax and food samples were also characterized. Plant-based FCMs do not pose a risk of phenanthrene and anthracene migration into Tenax. In turn, carbonyl compounds can migrate after short and long contact between the FCMs and food simulant. However, aldehydes may degrade with prolonged contact of food with FCMs. In addition, BPA, BPS, benzophenone derivatives and phthalates may migrate from the FCMs into Tenax. Moreover, some contaminants can migrate at concentrations above the specific migration limits (e.g. BPA). The intensity of migration process may depend on the structure of the molecule and the size of the substituents.

Phthalate exposure in primary school children: concentrations, oral intake, and risk assessment in Jinan, China

Phthalates in indoor environments can enter the human body through non-dietary exposure routes. Excessive exposure to phthalates in children may cause health issues. We examined exposure concentrations, oral intake, and risks for primary-school students in their living environments (home, classroom, and outdoor) in Jinan. We collected 138 dust samples and focused on 13 common phthalates. Phthalates were ubiquitous across all environments, with di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DnBP), and di-iso-butyl phthalate (DiBP) representing the highest proportions. Concentrations varied by environment: girls' bedrooms > boys' bedrooms, girls' living rooms > boys' living rooms, homes > classrooms > outdoors, and urban outdoors > suburban outdoors. Factors such as PM2.5 levels, the use of personal care products, item types, and fabric types influenced indoor phthalate concentrations. Oral exposure data showed that the home is the primary exposure environment, accounting for 51%-88%, followed by the classroom and outdoor environments. The carcinogenic risk associated with DEHP exceeded acceptable limits for all children, with four children exhibiting hazard index values greater than 1. We provide significant data on phthalate exposure in primary school children and suggest that exposure reduction strategies should focus on DEHP, DnBP, and DiBP in both homes and classrooms.

Infants exposure to chemicals in diapers: A review and perspective

Diapers are a staple care product for infants, yet concerns persist regarding the potential risks posed by dermal exposure to chemicals through their usage. This review provides a comprehensive summary of reported chemicals, highlighting the frequent detection of polychlorodibenzo-p-dioxins (PCDDs), phthalates (PAEs), volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), bisphenols (BPs), organotins, and heavy metals. Disposable diapers commonly exhibit higher concentrations of VOCs, PAEs, BPs, and heavy metals than other chemicals. Our estimation reveals formaldehyde as posing the highest dermal exposure dose, reaching up to 0.018 mg/kg bw/day. Conversely, perfluorooctanoic acid (PFOA) exhibits lower exposure, but its non-cancer hazard quotient (0.062) is the highest. In most scenarios, the risk of chemical exposure through diapers for infants is deemed acceptable, while the risk is higher under some extreme exposure scenarios. Using the cancer slope factor recently suggested by U.S. EPA, the cancer risk in diapers raised by PFOA is 5.5 × 10-5. It should be noted that our estimation is approximately 1000-10,000 folds lower than some previous estimations. The high uncertainties associated with exposure and risk estimations are primarily raised by unclear parameters related to chemical migration coefficients, absorption factors, concentrations, and toxicity data for skin exposure, which requires research attention in future. Besides that, future research endeavors should prioritize the identification of potential toxic chemicals and the development of hygiene guidelines and standards.

Non-dietary exposure to phthalates in primary school children: Risk and correlation with anthropometric indices, cardiovascular and respiratory diseases

Phthalates are endocrine disruptors of increasing concern for human health; however, previous studies have only assessed the association between internal exposure and human health. We aimed to assess the non-carcinogenic and carcinogenic risks of non-dietary exposure to phthalates in indoor environments among primary school children and their correlations with health indicators. A study involving 54 children was conducted in Jinan, Shandong Province, China. Questionnaires and health examinations were conducted, dust in hard-to-clean corners of students' classrooms and homes was collected, and airborne phthalates in the middle of classrooms and family living rooms were sampled. The gas-phase phthalate concentrations, individual exposure, and non-carcinogenic and carcinogenic risks were calculated. Associations were estimated using linear mixed models. The findings revealed that phthalates posed a non-carcinogenic risk to 7.4 % of the children and a moderate carcinogenic risk to 27.8 % of the children, with higher non-carcinogenic and carcinogenic risks to girls than to boys. Five phthalates were negatively correlated with body mass index, dimethyl phthalate and diethyl phthalate (DEP) were significantly correlated with waist circumference, and di-iso-butyl phthalate (DiBP) was negatively correlated with hip circumference. DiBP, di-n-butyl phthalate, and DEP, were significantly correlated with cardiovascular disease, DEP and di (2-n-butoxyethyl) phthalate were correlated with decreased lung function, and di-n-octyl phthalate influenced airway inflammation. The findings indicated that phthalate exposure may negatively impact children's health, thereby warranting further comprehensive research on the health effects of these chemicals.

Dimethyl phthalate exposure induces cognitive impairment via COX2-mediated neuroinflammation

AIM

The present work explored the mechanism of dimethyl phthalate (DMP, the environmental contaminant) exposure in inducing cognitive impairment.

METHODS

Targets and regulatory networks related to DMP-brain injury-cognitive impairment were analyzed through network pharmacology. DMP exposure was carried out to simulate DMP environmental uptake, whereas Morris water maze was performed for examining cognitive impairment. Additionally, inflammatory cytokine levels within tissues were measured. hematoxylin-eosin staining(H&E) and Nissl staining was conducted to examine brain tissue injury, while Western blot was carried out for identifying protein levels. After applying.Small interfering RNA(siRNA-COX2) and celecoxib-COX2 inhibitors separately, we analyzed impacts of DMP. Besides, in vitro experiments were performed to analyze impacts of DMP on microglial activation.

RESULTS

As suggested by network pharmacology,Cyclooxygenase-2-PTGS2 (COX2) showed significant relation to DMP, and it exerted its effect via COX2. Following DMP exposure, mice experienced obvious cognitive impairment and brain damage, besides, microglial cells were activated, and inflammatory cytokines were up-regulated. Applying siRNA-COX2 and celecoxib-COX2 suppressed DMP's impact and mitigated mouse cognitive impairment. Based on in vitro analysis, DMP led to microglial activation and neuroinflammation.

CONCLUSION

DMP exposure causes neuroinflammation via the COX2-regulated microglial activation, thus leading to cognitive impairment. COX2 may serve as the key action target of DMP.

Silicone wristbands reveal ubiquitous human exposure to ortho-phthalates and non-ortho-phthalate plasticizers in Southern California

In the United States and abroad, ortho-phthalates and non-ortho-phthalate plasticizers continue to be used within a diverse array of consumer products. Prior California-specific biomonitoring programs for ortho-phthalates have focused on rural, agricultural communities and, to our knowledge, these programs have not measured the potential for exposure to non-ortho-phthalate plasticizers. Therefore, the potential for human exposure to ortho-phthalates and non-ortho-phthalate plasticizers have not been adequately addressed in regions of California that have higher population density. Since there are numerous sources of ortho-phthalates and non-ortho-phthalate plasticizers in population-dense, urban regions, the objective of this study was to leverage silicone wristbands to quantify aggregate ortho-phthalate and non-ortho-phthalate plasticizer exposure over a 5-day period across two different cohorts (2019 and 2020) of undergraduate students at the University of California, Riverside (UCR) that commute from all over Southern California. Based on 5 d of aggregate exposure across two different cohorts, total ortho-phthalate plus non-ortho-phthalate plasticizer concentrations ranged, on average, from ∼100,000-1,000,000 ng/g. Based on the distribution of individual ortho-phthalate and non-ortho-phthalate plasticizer concentrations, the concentrations of di-isononyl phthalate (DiNP, a high molecular weight ortho-phthalate), di (2-ethylhexyl) phthalate (DEHP, a high molecular weight ortho-phthalate), and di-2-ethylhexyl terephthalate (DEHT, a non-ortho-phthalate plasticizer) detected within wristbands were higher than the remaining seven ortho-phthalates and non-ortho-phthalate plasticizers measured, accounting for approximately 94-97% of the total mass depending on the cohort. Overall, our findings raise concerns about chronic DiNP, DEHP, and DEHT exposure in urban, population-dense regions throughout California.

Occurrence, distribution and risk assessment of phthalate esters in dust deposited in the outdoor environment of Yazd industrial park using Monte Carlo simulation

In this study, the distribution of eight phthalate esters (PAEs), namely (dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), bis (2-ethylhexyl) phthalate (DEHP), and di-n-octyl phthalate (DnOP)) were examined across fifteen sampling stations in Yazd industrial Park. All the PAEs in dust deposited in the outdoor environment were analyzed using a Gas-mass chromatography (GC-MS/MS) device. Both probabilistic and deterministic approaches were utilized to assess the non-carcinogenic and carcinogenic health risks for adult occupational population groups. These risks were associated with three exposure pathways: inhalation, ingestion, and dermal exposure to six phthalates in the dust samples. The findings revealed, among the fifteen sampling stations, highest and lowest concentrations of the PAEs in dust deposited in the outdoor environment were observed in S8 and S6, with BEHP (326.21 ± 4.35) μg/g and DMP (0.00 ± 0.02) μg/g, respectively. The total hazard index (HI) values were below one in all samples, indicating that the combined non-carcinogenic health risk from exposure to phthalates via inhalation, ingestion, and dermal pathways is within acceptable levels in each studied area. The total cancer risk (CR) values for BBP across all exposure routes were consistently low, with magnitudes ranging from 10- x 10-15to 10 x 10-11. The order of cancer risk from phthalate exposure in outdoor environments was ingestion > dermal > inhalation. The sensitivity analysis (SA) results indicated that the influential parameters in the carcinogenic risk in adult occupational population groups were concentration for inhalation and dermal pathways, as well as ingestion rate for the ingestion pathway. The result of this study provides new insight in to PAEs pollution and risk assessments related to the dust deposited in the outdoor environment of industrial Park. Furthermore, this finding is beneficial to the controlling the exposure and promoting steps to reduce PAEs contamination and manage health in the industrial area.

Phthalate monoesters accumulation in residential indoor dust and influence factors

Phthalate monoesters (mPAEs) possess biological activity that matches or even exceeds that of their parent compounds, phthalate esters (PAEs), negatively impacting humans. Indoor dust is the main carrier of indoor pollutants. In this study, indoor dust samples were collected from 46 households in Changchun City, Jilin Province, in May 2019, and particulate and flocculent fibrous dust was used as the research target to analyze the concentration and compositional characteristics of mPAEs, primary metabolites of five significant PAEs. The influence of factors such as architectural features and living habits in residential areas on exposure to mPAEs was explored. Ten suspected enzyme genes along with two metabolic pathways with the ability to degrade PAEs were screened using PICRUSt2. The results showed that the total concentrations of the five mPAEs in the indoor dust samples were particulate dust (11.49-78.69 μg/g) and flocculent fibrous dust (21.61-72.63 μg/g), respectively. The molar concentration ratio (RC) of mPAEs to corresponding PAEs significantly differed among chemicals, with MMP/DMP and MEP/DEP sporting the highest RC values. Different bacterial types have shown distinct influences against mPAEs and PAEs. Enzyme function and metabolic pathway abundance had a significant effect on the concentration of some mPAEs, mPAEs are most likely derived from microbial degradation of PAEs.

Efficient remediation of di-(2-ethylhexyl) phthalate and plant-growth promotion with the application of a phosphate-solubilizing compound microbial agent

The ecotoxic endocrine-disrupting chemical di-(2-ethylhexyl) phthalate (DEHP) is ubiquitous in agricultural soil, posing a serious threat to human health. Here, we report efficient soil-borne DEHP degradation and plant growth promotion by a microbial organic fertilizer GK-PPB prepared by combining a recycled garden waste-kitchen waste compost product with ternary compound microbial agent PPB-MA, composed of Penicillium oxalic MB08F, Pseudomonas simiae MB751, and Bacillus tequilensis MB05B. The combination of MB08F and MB751 provided synergistic phosphorus solubilization, and MB05B enhanced the DEHP degradation capacity of MB08F via bioemulsification. Under optimal conditions (25.70 °C and pH 7.62), PPB-MA achieved a 96.81 % degradation percentage for 1000 mg L-1 DEHP within 5 days. The degradation curve followed first-order kinetics with a half-life of 18.24 to 24.76 h. A complete mineralization pathway was constructed after identifying the degradation intermediates of 2H-labeled DEHP. Evaluation in Caenorhabditis elegans N2 showed that PPB-MA eliminated the ecological toxicity of DEHP. A pakchoi (Brassica chinensis L.) pot experiment demonstrated that GK-PPB promoted phosphorus solubilization and plant growth, reduced soil DEHP residue, and decreased DEHP accumulation in pakchoi, suggesting its potential practical utility in environmentally responsible and safe cultivation of vegetables.