House dust is an important medium for exposure to persistent pollutants, such as metals. Detailed characterization of metal composition is needed to identify sources and potential health impacts of exposure. In this study we show that specific metals in dust dominate in different locations within residential homes in a mid-size Canadian city (Fort McMurray, Alberta), up to two years after a major wildfire event in 2016. Dust samples were collected in high-traffic (e.g. bedroom, N = 186), low-traffic (e.g. basement, N = 158), and entranceway areas (N = 171) of residential homes (N = 125), and analyzed for 25 trace metal elements using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The profile of metal concentrations in the entranceway resembled that of outdoor soils, especially for crustal elements. On the other hand, Cu, Zn, and Pb concentrations in dust sampled in indoor living areas were on average three to six times higher than in other indoor locations indicating indoor sources for these elements. In general, Pb concentrations were similar or lower than in an average Canadian residence, but a substantial fraction showed anomalously high concentrations in the low-traffic areas, particularly on concrete surfaces in basements. Notably, the 2016 wildfires showed limited influence on metal concentrations in indoor dust, despite the widespread concerns in the community about long term exposure. Enrichment factor ratio calculations and principal component analysis showed two classes of sources of metals in dust that represent geogenic-outdoor sources and anthropogenic-indoor sources. Overall, we demonstrate that outdoor and indoor sources of dust impact its composition, and these influences are reflected in the different areas of a home.

Maintaining thyroid homeostasis during pregnancy is vital for fetal development. The few studies that have investigated associations between metal exposure and gestational thyroid function have yielded mixed findings. To evaluate the association of exposure to a mixture of toxic metals with thyroid parameters in 824 pregnant women from the Rhea birth cohort in Crete, Greece. Concentrations of three toxic metals [cadmium (Cd), antimony (Sb), lead (Pb)] and iodine were measured in urine using inductively coupled plasma mass spectrometry and thyroid hormones [Thyroid Stimulating Hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3)] were measured in serum in early pregnancy. Associations of individual metals with thyroid parameters were assessed using adjusted regression models, while associations of the metal mixture with thyroid parameters were assessed using Bayesian Kernel Machine Regression (BKMR).Women with high (3rd tertile) concentrations of urinary Cd, Sb and Pb, respectively, had 13.3 % (95%CI: 2.0 %, 23.2 %), 12.5 % (95%CI: 1.8 %, 22.0 %) and 16.0 % (95%CI: 5.7 %, 25.2 %) lower TSH compared to women with low concentrations (2nd and 1st tertile). In addition, women with high urinary Cd had 2.2 % (95%CI: 0.0 %, 4.4 %) higher fT4 and 4.0 % (95%CI: −0.1 %, 8.1 %) higher fT3 levels, and women with high urinary Pb had 4 % (95%CI: 0.2 %, 8.0 %) higher fT3 levels compared to women with low exposure. The negative association of Cd with TSH persisted only when iodine sufficiency was unfavorable. BKMR attested that simultaneous exposure to toxic metals was associated with decreased TSH and increased fT3 and revealed a potential synergistic interaction of Cd and Pb in association with TSH. The present results suggest that exposure to toxic metals even at low levels can alter gestational thyroid homeostasis.

Exposure to methylmercury (MeHg) through fish is a global public health problem. Exposure monitoring is essential for health risk assessment, especially in pregnant women and children due to the documented neurotoxicity. Herein, we evaluate a time series of MeHg exposure via fish in primiparous Swedish women, covering a time period of 23 years (1996–2019). The 655 included mothers were part of the POPUP study (Persistent Organic Pollutants in Uppsala Primiparas) conducted by the Swedish Food Agency (SFA). MeHg exposure was assessed via measurements of total mercury (Hg) in hair using either cold vapor atomic fluorescence spectrophotometry or inductively coupled plasma mass spectrometry, showing very good linear agreement (R² = 0.97). Maternal characteristics and fish consumption were obtained via questionnaires. The median concentration of total Hg in hair was 0.38 mg/kg (range 0.17–1.5) in 1996 and 0.25 mg/kg (range 0.03–1.1) in 2019. On average the women consumed 11 ± 8.2 meals of fish per month, and fish consumption was positively correlated with total Hg in hair (Spearman correlation: 0.39; p < 0.001). In multiple regression analyses, the geometric mean annual decrease of total Hg in hair was −2.5% (95% CI: -3.2, −1.8%). Total fish consumption increased up to 2011 (B: 0.32 times/month per year; 95% CI 0.17, 0.46) after which it started to decline (B: -0.66 times/month per year; 95% CI -0.92, −0.40). Moreover, both total Hg in hair and fish consumption was positively associated with maternal age and education, and inversely associated with pre-pregnancy BMI. In conclusion, the exposure to MeHg via fish appears to be slowly declining among Swedish pregnant women.

Lead poisoning of wild birds by ingestion of lead ammunition occurs worldwide. Histopathological changes in organs of lead-intoxicated birds are widely known, and lead concentration of each organ is measurable using mass spectrometry. However, detailed lead localization at the suborgan level has remained elusive in lead-exposed birds. Here we investigated the detailed lead localization in organs of experimentally lead-exposed ducks and kites by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). In both the ducks and kites, lead accumulated diffusely in the liver, renal cortex, and brain. Lead accumulation was restricted to the red pulp in the spleen. With regard to species differences in lead distribution patterns, it is noteworthy that intensive lead accumulation was observed in the arterial walls only in the kites. In addition, the distribution of copper in the brain was altered in the lead-exposed ducks. Thus, the present study shows suborgan lead distribution in lead-exposed birds and its differences between avian species for the first time. These findings will provide fundamental information to understand the cellular processes of lead poisoning and the mechanisms of species differences in susceptibility to lead exposure.

With the constant quest for new sources of superfoods to supplement the largely nutrient deficient diet of the modern society, sea cucumbers are gaining increasing popularity. Three species of sea cucumbers, Cucumaria frondosa, Apostichopus californicus and Apostichopusjaponicus were collected from three geographical regions, Atlantic and Pacific coast of Canada and Yellow sea/ East China sea in China, respectively. These organisms were sectioned into parts (body wall, tentacles, internal organ, skin and muscle) and analysed for total arsenic (As) by inductively coupled plasma mass spectrometry (ICP-MS) and As species by high-performance liquid chromatography (HPLC) coupled to ICP-MS. Normal and reversed sequential extractions were optimised to address As distribution between lipids (polar and non-polar) and water-extractable fractions. Two extraction methods for water-extractable As were compared in terms of the number and the amount of extracted species. The results revealed that total As concentration and As species distribution varies significantly between sea cucumbers species. Total As in studied body parts ranged between 2.8 ± 0.52 and 7.9 ± 1.2 mg kg⁻¹, with an exception of the muscle tissue of A. californicus, where it reached to 36 ± 3.5 mg kg⁻¹. Arsenobetaine (AsB) was the most abundant As species in A. californicus and A.japonicus, however, inorganic As represented over 70% of total recovered As in the body parts of C. frondosa. Arsenosugars-328 and 482 were found in all studied body parts whereas arsenosugar-408 was only found in the skin of A. californicus. This is the first time that such a variation in As species distribution between sea cucumber species has been shown.

Although plants are often exposed to atmospheric nanoparticles (NPs), the mechanism of NP deposition and their effects on physiology and metabolism, and particularly in combination with other stressors, are not yet understood. Exploring interactions between stressors is particularly important for understanding plant responses in urban environments where elevated temperatures can be associated with air pollution. Accordingly, 3-year-old spruce seedlings were exposed for 2 weeks to aerial cadmium oxide (CdO) NPs of environmentally relevant size (8–62 nm) and concentration (2 × 10⁵ cm⁻³). While half the seedlings were initially acclimated to high temperature (35 °C) and vapour pressure deficit (VPD; 2.81 kPa), the second half of the plants were left under non-stressed conditions (20 °C, 0.58 kPa). Atomic absorption spectrometry was used to determine Cd content in needles, while gas and liquid chromatography was used to determine changes in primary and secondary metabolites. Photosynthesis-related processes were explored with gas-exchange and chlorophyll fluorescence systems. Our work supports the hypothesis that atmospheric CdO NPs penetrate into leaves but high temperature and VPD reduce such penetration due to stomatal closure. The hypothesis that atmospheric CdO NPs influences physiological and metabolic processes in plants was also confirmed. This impact strengthens with increasing time of exposure. Finally, we found evidence that plants acclimated to stress conditions have different sensitivity to CdO NPs compared to plants not so acclimated. These findings have important consequences for understanding impacts of global warming on plants and indicates that although the effects of elevated temperatures can be deleterious, this may limit other forms of plant stress associated with air pollution.

There is increasing evidence linking levels of trace elements (TEs) in adipose tissue with certain chronic conditions (e.g., diabetes or obesity). The objectives of this study were to assess concentrations of a selection of nine essential and possibly-essential TEs in adipose tissue samples from an adult cohort and to explore their socio-demographic, dietary, and lifestyle determinants. Adipose tissue samples were intraoperatively collected from 226 volunteers recruited in two public hospitals from Granada province. Trace elements (Co, Cr, Cu, Fe, Mn, Mo, Se, V, and Zn) were analyzed in adipose tissue by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). Data were collected on socio-demographic characteristics, lifestyle, diet, and health status by face-to-face interview. Predictors of TE concentrations were assessed by using multivariable linear and logistic regression. All TEs were detected in all samples with the exception of Se (53.50%). Iron, zinc, and copper showed the highest concentrations (42.60 mg/kg, 9.80 mg/kg, and 0.68 mg/kg, respectively). Diet was the main predictor of Cr, Fe, Mo, and Se concentrations. Body mass index was negatively associated with all TEs (β coefficients = −0.018 to −0.593, p = 0.001–0.090) except for Mn and V. Age showed a borderline-significant positive correlation with Cu (β = 0.004, p = 0.089). Residence in a rural or semi-rural area was associated with increased Co, Cr, Fe, Mo, Mn, V and Zn concentrations and with β coefficients ranging from 0.196 to 0.544 (p < 0.05). Furthermore, individuals with higher educational level showed increased Cr, Co, Fe and V concentrations (β coefficients = 0.276–0.368, p = 0.022–0.071). This is the first report on the distribution of these TEs in adipose tissue and on their determinants in a human cohort and might serve as an initial step in the elucidation of their clinical relevance.

The long-term associations between multiple metals and incident diabetes are uncertain. We aimed to examine the relationship between plasma concentrations of 23 metals and the incidence of type 2 diabetes among Chinese senior adults. We quantified fasting plasma concentrations of 23 metals by inductively coupled plasma mass spectrometry among 1039 incident diabetes cases and 1039 controls (age and sex matched) nested in a prospective study, the Dongfeng-Tongji cohort. Both cases and controls were free of diabetes at baseline (2008–2010), incident diabetes were identified using the following criteria: fasting glucose ≥ 7.0 mmoL/l; or hemoglobin A1c (HbA1c) ≥ 6.5%; or self-reported physician diagnosis of diabetes or use of anti-diabetic medication during the follow-up visits in 2013. In the conditional logistic regression models, the multivariable adjusted ORs (95% CIs) of diabetes across quartiles (Q1–Q4) of metal concentrations were as follows: titanium, 1.00, 0.92, 1.31, 1.38 (1.00–1.91, Ptrend = 0.011); selenium, 1.00, 1.08, 1.45, 1.27 (0.93–1.74, Ptrend = 0.05); and antimony, 1.00, 0.79, 0.77, 0.60 (0.44–0.83, Ptrend = 0.002). Arsenic was significantly associated with diabetes in the crude model (ORs comparing extreme quartiles 1.30; 1.02–1.65; Ptrend = 0.006), but was not significant after adjustment for socio-demographic factors. No significant associations were found for other metals. In conclusion, titanium and selenium were positively while antimony was negatively associated with incident diabetes.

The placenta is an intermediary organ between the female and the developing foetus. Some chemical substances, including the most harmful ones, exhibit the ability to accumulate in or penetrate through the placenta. The aim of the study was to determine the role of the placenta of the Baltic grey seal (Halichoerus grypus grypus) in the transfer of endocrine disrupting compounds (EDCs) - (bisphenol A, 4-tert- octylphenol, 4- nonylphenol), as well as total and organic mercury. 30 placentas were collected from grey seals pupping under human care at the Hel Marine Station in the years 2007–2016. The assays were conducted using the technique of high-preformance liquid chromatography (phenol derivatives) and atomic absorption spectrometry (mercury and selenium). A measurable level of EDCs was indicated in the placentas of grey seals. It was established that the inorganic Hg form was accumulated in the placenta, and that its concentrations were an order of magnitude higher than the concentrations of the organic form, which penetrated to the foetus. Similar observations were made for phenol derivatives - bisphenol A, 4-tert- octylphenol and 4-nonylphenol. For this compound group the placenta was a barrier, but the properties of phenol derivatives suggest the possibility of their penetration through this organ.

Exposure to lead(Pb) or cadmium(Cd) has been related to decreasing thyroxine in many previous studies. The underlying mechanisms have not been clarified. Heavy metal-induced thyroid autoimmunity in pregnant women has been found, despite having been rarely explored in the general population.We aimed to determine whether the blood levels of lead(BPb) or cadmium(BCd) related to the levels of sera antibodies to thyroid proteins and thyroid dysfunction in the general population.Our study included 5628 Chinese adults and was based on the 2014 SPECT-China study. Thyroid dysfunction and subclinical thyroid dysfunction were defined by total triiodothyronine (TT3), total thyroxine(TT4) and thyroid stimulating hormone (TSH).Thyroid peroxidase antibody (TPOAb), thyroglobulin antibodies (TGAb), TT3, TT4, and TSH were measured by immunochemiluminometric assays. BPb and BCd levels were tested by atomic absorption spectrometry. Linear and logistic regression models were used to analyze the associations.After adjustment for age, body mass index, smoking status (men only) and drinking status, the natural log(ln) BPb was positively related to the lnTPOAb (B = 0.062, P < 0.05) and to the lnTSH (B = 0.047, P < 0.01) in women. The lnBCd in women was positively related to the lnTGAb (B = 0.046, P < 0.05). In the adjusted logistic regression models, the BCd of women was positively related to their hypothyroid status and TGAb tertiles. The ORs of women in the middle and higher TPOAb tertiles were 1.38 (P < 0.001) and 1.35 (P < 0.001) times greater for every ln-unit increase in BPb, respectively. In men, no continuous correlation was found among variables.In women, BPb and BCd levels were related to higher TSH and hypothyroid status, respectively, suggesting a Pb and Cd induction of sex-biased thyroid autoimmunity.