Plastics have become a pervasive global contaminant since the mid-20th century, causing harm to organisms at all levels. Preventative measures to reduce plastic pollution and awareness-raising campaigns about the damaging effects of plastic debris on the environment and its inhabitants are crucial; however, most plastic assessments focus on singular trophic levels. Microplastics, tiny plastic particles ranging from 25 μm to 5 mm, have emerged as a widespread form of pollution found in ecosystems worldwide. They can enter the environment directly or through the breakdown of larger plastic debris and are thought to be mistaken for food by foraging animals. This leads to microplastics circulating through ecosystems via direct and indirect consumption, ultimately impacting even higher-order predators. Here, we assess the impacts of microplastics on Chlorophyll a concentrations, algal community structure, copepod survivorship, and fish behavior in experimental trials, in addition to simulated top-predator foraging success on plastic-exposed fish. Our results indicate that microplastics have detrimental effects on algal growth and copepod survival. We also observed the trophic transmission of small plastic spheres from copepods to fish predators, highlighting a concerning pathway for microplastic pollution within aquatic ecosystems, where fish consumed plastics through direct and indirect means. Primary consumers, like copepods, face dual pressures from top-down forcing, as they are preferred over plastic particles as food sources, and bottom-up resource depletion, as algal food supplies can be limited by microplastic exposure. Our findings demonstrate the system-wide impacts that can occur when microplastics are included in food chains and underscore the urgent need for comprehensive strategies to mitigate the entry of plastic debris into aquatic ecosystems.

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) were measured in 298 human milk samples collected from across Canada between 2008 and 2011 as part of the Maternal-Infant Research on Environmental Chemicals study. PBDEs were detected in 100% of the samples analyzed and concentrations ranged from 0.071 to 267 ng·g^-1 lipid (median 15.6 ng·g^-1 lipid). The dominant contributors to ΣPBDEs (Σ15, 17, 28, 37, 47, 66, 71, 75, 77, 85, 99, 100, 119, 138, 153, 154, 160, 183, 190, 209) were PBDE 47 > PBDE 153 > PBDE 99 > PBDE 100 > PBDE 28 > PBDE 209. Previously, PBDE 209 was considered to be a minor contributor to ΣPBDE concentrations in Canadian human milk and, therefore, not reported by our lab. This study showed that when present, PBDE 209 can be an important contributor to ΣPBDEs (range: below detection - 85.3 ng·g^-1 lipid; median - 0.083 ng·g^-1 lipid). ΣPBDE concentrations declined slightly in Canadian human milk between the early and late 2000s. HBCD (Σ of α-, β-, and γ-) was observed in 94.0% of the samples measured and concentrations were dominated by α-HBCD (93.3%), with β- (9.7%) and γ- (28.5%) less frequently detected. The maximum ΣHBCD concentration observed was 7.66 ng·g^-1 lipid (median value 0.303 ng·g^-1 lipid). These data suggest that HBCD concentrations similarly decreased in Canadian human milk between the early 2000s and sampling for the present study. Maternal age did not impact the concentrations of these flame retardants in milk. Additionally, other maternal characteristics [e.g., the number of children a woman has had, pre-pregnancy body mass index (BMI), and education level] did not impact concentrations of these brominated flame retardant concentrations.

Hairdressers are exposed to volatile organic compounds (VOCs) that can pose health risks. Women of color (Black/Latina) represent nearly one-third of all U.S. hairdressers who may be disproportionally exposed to VOCs through occupational and personal use of hair products and treatments specifically formulated for this demographic. Still, data on workplace VOC exposures in this workforce remains sparse. We conducted area air monitoring of 14 VOCs in three salons serving Black women (“Black salons”), three Dominican salons predominantly serving Latino and Black women and 10 office spaces using active integrated sampling across 8-hour work shifts. Most VOCs measured were detected in hair salons (n = 13) and offices (n = 11). Salons had median VOC concentrations 2-175 times higher than offices. Among salons, 95th percentile VOC concentrations were up to 187 times higher in Black salons than in Dominican salons, suggesting that elevated exposures may occur partly from differences based on product use, services rendered, and salon characteristics (e.g., cleaning practices, ventilation). This is the first study to report indoor air concentrations of multiple individual targeted VOCs in U.S. hair salons serving women of color, highlighting the need for comprehensive exposure studies and assessment of potential health risks in this understudied and overexposed workforce.

The diesters of 1,2-benzenedicarboxylic acid (phthalic acid), or phthalates, are multifunctional chemicals used in personal care products, medications, and plastics. Phthalate metabolites are also found in human milk and infant formula. However, their impact on intestinal development and microbiota composition in early life is understudied. Herein, the effect of di-(2-ethylhexyl) phthalate (DEHP) on growth, intestinal morphology, enzyme activity, and microbiota composition was assessed. Piglets (two-day-old, n = 24) were randomized to receive either 20 mg (DEHP20) or 200 mg (DEHP200)/kg body weight (BW)/day in corn oil. A control group (CON, 0 mg phthalate) received the same volume of corn oil as DEHP200. After 21 days, tissue and urine samples were collected. DEHP did not affect weight gain. Urinary DEHP metabolite concentrations increased in a dose-dependent fashion. Jejunal villus length was significantly shorter in the DEHP200 than CON and DEHP20, while villus area was smaller in DEHP200 than DEHP20 but not CON. Crypt depth and area were higher in DEHP200 than DEHP20, but neither differed from CON. Additionally, jejunal sucrase activity was higher in the DEHP200 than CON. Bacterial alpha diversity differed significantly between DEHP groups and CON in the ascending colon, while beta diversity revealed significant differences between DEHP200 and CON and DEHP20. The abundance of Christensenellaceae R-7 group, Romboutsia, Lachnospiraceae UCG-004, Odoribacter, and Sphaerochaeta, among others, differed in DEHP-exposed vs. CON animals. Thus, daily exposure to phthalates during infancy changes the villus structure and disaccharidase activity in the small intestine and these changes may be modulated by the colonic bacterial community.

Hair provides an excellent matrix for long-term biomonitoring due to its chemical accumulation during growth. Despite recent uses of hair for biomonitoring to characterize the chemical exposome across demographics, no established baseline exists for the hair metabolome based on age and sex. This study aimed to establish a baseline for the hair metabolome influenced by age and sex, utilizing an Orbitrap mass spectrometer, a high-resolution mass spectrometry (HRMS) technique. We collected hair samples from 48 participants divided by age and sex into four groups: elderly males, elderly females, young males, and young females. Metabolic profiling was conducted using ultrahigh-performance liquid chromatography coupled with Q Exactive^TM Plus Orbitrap mass spectrometer. Our analysis revealed significant age- and sex-dependent variations in metabolite profiles. Volcano plots highlighted the differential metabolic features between groups, with age showing a stronger influence on metabolic variations in females and sex in younger individuals. We identified 205 chemical compounds affected by age and/or sex, with a significant portion showing overlap in their influence. Pathway enrichment analysis pinpointed perturbations in 41 metabolic pathways, including those involved in lipid metabolism, amino acid turnover, and hormone-associated pathways. Notably, the pathways of arachidonic acid metabolism and fatty acid biosynthesis were consistent with known age and sex influences. Our findings underscore the potential of using hair metabolomics for comprehensive environmental exposure assessment and health research, offering insights into the biological impact of age and sex on the human metabolome.

Fuel spills pose significant environmental risks, particularly to drinking water sources and aquatic ecosystems. The composition of fuels has changed over the decades to reduce fossil greenhouse gas emissions. In Sweden, although the number of spill incidents has declined, with around 600 cases reported annually, there remains limited knowledge on the environmental and health impacts of modern fuels. This study aimed to address this gap through comprehensive chemical analysis and ecotoxicological assessments of 31 fuel samples, including petrol, diesel, fuel oil, and marine gas oil. Using gas chromatography-mass spectrometry (GC-MS), we determined 53 substances, including aromatic and aliphatic hydrocarbons, ethers, esters, and 17 polycyclic aromatic hydrocarbons (PAHs). A key focus was on forming a stable water-accommodated fraction (WAF) to isolate non-dissolved fuel elements from water, which is crucial for assessing subsurface aquatic life and drinking water production impacts. Results indicated significant differences in fuel odor profiles, with ethers enhancing odor intensity. Petrol components showed higher water solubility than diesel, partly due to ethanol. Ecotoxicological tests revealed varying toxicity across fuels, with petrol showing the highest toxicity to aquatic organisms, although activated sludge exhibited resilience. Fuels containing water-soluble ethers posed the highest risks to drinking water, while modern diesel was of lower concern due to its low solubility and toxicity. In freshwater ecosystems, petrol and hydrophobic toxins in fuel oil had severe effects during spills. Overall, this study offers critical insights into the environmental impact of common fuels, supporting improved risk assessment and management strategies for spill mitigation and water resource protection.

Tetramethylammonium hydroxide (TMAH) is extensively utilized in the semiconductor and optoelectronic industries, serving as either a developer or an etchant. TMAH possesses acute toxicity and alkaline corrosiveness, having caused several fatal and injurious accidents in Taiwan. However, there is currently a lack of methods available for assessing TMAH exposure. This study developed a method involving sampling with quartz fiber filters followed by ultrasonic agitation in 10 mL mobile phase, filtering, and analysis using either ion chromatography (IC) or ultra-performance liquid chromatography - high-resolution mass spectrometry (UPLC-HRMS). Utilizing the characteristics of HRMS, the compound analyzed was identified as tetramethylammonium ion (TMA⁺) through mass spectrometry analysis. The method exhibits excellent trapping capacity and recovery rate. The linear range of TMA⁺ for IC is 0.3 to 100 μg/mL, with a correlation coefficient of R = 0.9998. The linear range of TMA⁺ for UPLC-HRMS is 0.002 to 1 μg/mL, with a correlation coefficient of R = 0.996. The recovery rates for IC and HRMS were 116.6% and 90.6%, with corresponding coefficient of variation (CV) of 2.25% and 3.53%, respectively. Samples can be stored at room temperature for 28 days. Verification of this method was conducted at the TMAH factory, and the air concentrations measured in the TMAH filling area were 3.29 and 4.75 μg/m³ from IC and UPLC-HRMS, respectively. This method will be applied in the on-site analysis of occupational hazards for operators in chemical plants, technology factories, and recycling plants, aiming to evaluate risk values to protect the safety and health of workers and prevent occupational diseases.