Long-term exposure to airborne metals and risk of cancer in the French cohort Gazel

The impact of cadmium exposure on breast cancer risk: Exploring dose-response relationships and mediating effects

Cadmium (Cd), an endocrine disruptor, has been linked to hormone-related cancers, including breast cancer (BC). However, previous studies investigating the association between Cd exposure and BC risk have yielded inconsistent results, and the effects of Cd on BC subtypes remain poorly understood. We employed logistic regression and restricted cubic splines (RCS) to examine the relationship between Cd exposure and BC. A meta-analysis was subsequently conducted to validate the association between Cd exposure and BC. Lastly, mediation analysis was applied to explore the underlying mechanisms linking Cd exposure to BC. Data from 5954 participants in the National Health and Nutrition Examination Survey (1999-2020) were analyzed. Elevated Cd levels in the fourth quartile were significantly associated with an increased BC risk (odds ratio (OR) = 3.74, 95 % confidence interval (CI): 1.45 - 9.62, Ptrend = 0.019), compared to the first quartile group. A linear dose-response relationship was seen between urinary Cd levels and BC risk (Pnon-linear = 0.532), with BC risk increasing 317 % (OR = 3.17, 95 % CI: 1.93 - 5.20, Ptrend < 0.001) for 1 μg/g creatinine increases in urinary Cd levels. The meta-analysis, which included 20 eligible studies, further observed a possible link between Cd exposure and BC risk (relative risk (RR) = 1.17, 95 % CI: 1.06 - 1.29, I2 = 83 %), particularly in estrogen receptor-positive (ER+) subtypes (RR = 1.08, 95 % CI: 1.01 - 1.16, I2 = 70 %). Mediation analysis further revealed that glycated hemoglobin (HbA1c) mediated 9.09 % of the Cd-BC risk association. In conclusion, the study results suggest a potential association between Cd levels and an increased BC risk, particularly in ER+ subtypes. Mechanistically, HbA1c was identified as a mediator in this association. These findings underscore the complex interplay between Cd exposure and metabolic dysregulation in the development of BC, highlighting the potential role of HbA1c in modulating BC risk among individuals exposed to Cd.

Air pollution mapping and variability over five European cities

Mapping urban pollution is essential for assessing population exposure and addressing associated health impacts. High urban concentrations are due to the proximity of sources such as traffic or residential heating, and to urban density with the presence of buildings that reduce street ventilation. This urban complexity makes fine-scale mapping challenging, even for regulated pollutants such as NO2 and PM2.5. In this study we apply state-of-the-art empirical and deterministic modeling approaches to produce high-resolution (<100 m) pollution maps across five European cities (Paris, Athens, Birmingham, Rotterdam, Bucharest). These methodologies enable full-city mapping capturing intra-urban gradients of concentrations. Depending on the methodology, regulated pollutants (NO2, PM2.5) and/or emerging pollutants (black carbon (BC) and ultrafine particles (UFP characterized here by particulate number concentration PNC)) are considered. For deterministic modelling, different approaches are presented: a multi-scale Eulerian modelling chain down to the street scale with chemistry/aerosol dynamics at all scales, multi-scale hybrid models with Eulerian regional dispersion and Gaussian subgrid dispersion, and a Gaussian-based model. Empirical land use regression models were developed based upon mobile monitoring. To compare the relative performance of the methodologies and to evaluate their performance and limitations, the modelling results are compared to fixed measurement stations. We introduce a standardized metric to quantify spatial and seasonal variability and assess each method's capacity to reproduce fine-scale urban heterogeneity. We also evaluate how data assimilation affects both concentration accuracy and variability representation-particularly relevant for emerging pollutants where measurement data are sparse. We confirm established seasonal and spatial patterns: spatial variability is more pronounced for PNC, NO2 and BC than PM2.5, and concentrations are higher during the winter periods. We also observe reduced spatial variability in winter for PM2. 5 (linked to residential heating) and for BC in cities with significant wood burning emissions. This study adds unique value by evaluating these patterns using fixed measurement stations, and quantifying them across entire urban areas at very fine spatial resolution (<100 m). Furthermore, important methodological strengths and limitations are pointed out, providing practical guidance for the selection and improvement of urban exposure mapping methods, supporting the implementation of the new EU Air Quality Directive.

Associations between dietary exposure to profiles of metalloestrogens and estrogen-receptor positive breast cancer risk in the French E3N cohort

Metalloestrogens are ionic metals and metalloids that can activate estrogen receptor, and are suspected to play a role in breast cancer occurrence. This study explored the relationship between dietary exposure profiles to metalloestrogens and estrogen-receptor positive breast cancer (ERP-BC) risk among women in the French E3N cohort.A prospective study was conducted involving 66 722 women who completed a food frequency questionnaire in 1993. Food consumption data were combined with food contamination data obtained from the Second French Total Diet Study, to estimate the dietary intake of 14 metalloestrogens. A principal component analysis was performed to identify the main dietary exposure profiles to metalloestrogens. The retained principal components were included in Cox regression models, used to estimate Hazard Ratios (HR) and their 95% confidence intervals (95% CI) for the associations between the adherence to the identified profiles and ERP-BC risk identified until 2014, adjusted for confounding factors selected using a directed acyclic graph.After an average follow-up of 17.7 years, 3 739 incident cases of ERP-BC were identified. Four principal components were retained, explaining 80.5% of the variance. A statistically significant positive association between the third principal component, mainly characterized by dietary intake of inorganic arsenic and vanadium, and ERP-BC risk was estimated (HR: 1.04, 95% CI: 1.00-1.07, p-value: 0.03). No statistically significant association was found when evaluating the effect of each metalloestrogen individually.The results suggests that even relatively low levels of exposure to inorganic arsenic and vanadium, when combined, could increase the risk of ERP-BC.

Environmental pollution and health risks to informal workers: Exposure to heavy metals in human hair at Indonesian landfills

The concentration of heavy metals (HMs) in human hair is a bioindicator of environmental pollution over a long period from worker, including the informal worker at landfills. A landfill is where final-stage refuse is deposited, transported, and disposed of solid waste from urban areas. No study has been conducted on heavy metals in landfills and their health impact on informal workers. This study aims to investigate the accumulation of heavy metals over a long period, the effect of toxic metal exposure on the human body, and the health risks informal workers perceive as bioindicators of pollution in landfills. Human hair samples collected from informal workers and urban were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to measure HMs and human hair certified reference material (CRM) from the national institute for environmental studies, Japan. The sample consisted of individuals who were interviewed and had their hair cut. The total number of respondents in this study was 51 people. The average concentrations of the element heavy metals (µg/g) in informal workers are shown: Pb 4.70, As 0.30, Cd 1.07, Mn 14.58, Co 0.14, Cu 19.31, Fe 73.05, Zn 646.2, and Se 0.65. The results of our study the concentrations of heavy metals were higher than those found for urban residents. In the education level variable, 17.4 % of respondents did not attend school, 50 % attended primary school, and 32.6 % attended junior high school. Gender of respondents, 71.7 % are female, and in the working period, 69.6 % are more than ten years old. An epidemiological study and statistical analysis show the respondents' symptoms & health complaints such as cough, breathlessness, headache, nose irritation, variable mask, duration using a mask, and characteristics of the respondent's significant correlations p-value < 0.05 with a concentration of all metals. These findings show that the HMs have contaminated the environment and entered the human bodies, posing health risks to informal workers in the landfill working area.

Spatial extrapolation of cadmium concentration in terrestrial mosses using multiple linear regression model predictions across French biogeographical regions

The French Moss Survey employs forest mosses as indicators to monitor the deposition of atmospheric substances, notably focusing on cadmium (Cd), a known carcinogenic and contributor to respiratory illnesses. This comprehensive study encompasses 55 variables to understand Cd accumulation in terrestrial mosses in France. These variables include moss species, tree cover, biogeographical markers, land use area, proximity to road and rail networks, soil concentration of Cd and atmospheric concentration and deposition of Cd using a physical model. The response variable undergoes a complementary log-log transformation to constrain prediction values within the maximum Cd content in mosses. We have built a regression model to improve predictions, considering the impacts of covariates in France. This model retains biogeographical effects, leading to data segmentation into four distinct biogeographical zones: Atlantic, Continental, Mediterranean and Alpine. Subsequently, zone-specific regression models are explored to refine predictions and consider the impacts of covariates specific to each region, such as those related to railways and roads of the Mediterranean zone. Our biogeographical models effectively mitigate spatial correlation issues and yield accurate predictions, as evidenced by the leave-one-out cross-validation assessment. Compared to ordinary kriging map, the regression prediction maps highlight the contributions of certain covariates, such as the EMEP atmospheric transport model, to areas with high Cd concentrations. Furthermore, these maps exhibit new areas with high (resp. low) Cd concentrations due to high (resp. low) values of the covariates.

The Association Between Cadmium Exposure and Prostate Cancer: An Updated Systematic Review and Meta-Analysis

Prostate cancer (PCa) is a common cancer among men, and it has a multifactorial etiology. Cadmium (Cd), a toxic heavy metal classified as a carcinogen by the IARC, can cause various acute and chronic effects. This systematic review and meta-analysis aims to update previous findings on the association between Cd exposure and PCa. We carried out a literature search in PubMed, Web of Science, and Scopus up to May 2024, identifying eight new articles. The effect size from the highest and lowest exposure categories were extracted and analyzed using a random-effects model. Heterogeneity was assessed with the I2 test, and publication bias was evaluated using funnel plot asymmetry. Overall, the effect size for PCa associated with Cd exposure, combining previous and new articles, was 1.11 (95% CI 0.85-1.45). Heterogeneity was high, but no significant publication bias was detected. For studies from Europe, the effect size was 1.47 (95% CI 1.00-2.17). Notably, 11 articles from the previous systematic review and meta-analysis highlighted that higher Cd exposure is significantly associated with more aggressive histopathological types of PCa (OR 1.50, 95% CI 1.08-2.07). These findings suggest a potential public health concern, indicating the need for further research to clarify the risk associated with Cd exposure.

Association between Heavy Metals and Trace Elements in Cancerous and Non-cancerous Tissues with the Risk of Colorectal Cancer Progression in Northwest China

Alterations in heavy metals and trace element levels may be associated with various cancers. However, the role of this interaction in colorectal cancer (CRC) progression is unclear. In recent years, Principal Component Analysis (PCA) and Bayesian Kernel Machine Regression (BKMR) models have provided new ideas for analyzing the effects of metal mixtures on CRC progression. Herein, we assessed the differences in the levels of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), selenium (Se), and zinc (Zn) in tumors and adjacent healthy tissues, to investigate the relationship between heavy metals/trace elements and CRC progression. Surgical samples of CRC and noncancerous tissues were collected, and trace metal levels were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Logistic regression, PCA, and BKMR models were used to investigate the relationship between heavy metals and trace elements and the degree of tumor differentiation and lymph node metastasis in CRC. Cancer tissues showed lower As, Cd, Co, and Cr concentrations, and higher Se concentrations than healthy tissues (P < 0.05). In addition, CRC patients with poorly differentiated tumors and/or positive lymph node metastases had lower levels of Cd, Zn, Cu, and Se (P < 0.05). Logistic regression showed that single metal concentration was negatively correlated with CRC progression. PCA and BKMR models also showed that the metal mixture concentration was negatively correlated with CRC progression, with Cd contributing the most. Overall, changes in heavy metal and trace element levels may be related to the development of CRC; however, further mechanistic studies are required.

Association between exposure to heavy metals and the risk of breast cancer: A case-control study in Tanzania

Exposure to heavy metals is suspected to influence breast cancer development, although epidemiological evidence regarding this association remains controversial. This study investigated the association between urinary heavy metal levels and breast cancer risk through a hospital-based case-control design, involving 50 breast cancer patients and 40 healthy females. Heavy metals were quantified using an inductively coupled plasma atomic emission spectrophotometer (ICP-AES). The exposure levels were categorized into quartiles, and logistic regression was employed to evaluate the breast cancer risk associated with heavy metal exposure. The results revealed positive associations between risk of breast cancer and concentrations of Al, As, Ni, Cd, and Pb. In addition, the risk of breast cancer was high among participants in the 2nd, 3rd, and 4th quartiles of Al, As, Ni, Cd, and Pb. However, Co showed an inverse association with breast cancer. These results indicate that increased concentrations of heavy metals, with the exception of Co, are associated with the risk of breast cancer.

Ambient air pollution and urological cancer risk: A systematic review and meta-analysis of epidemiological evidence

Exposure to ambient air pollution has significant adverse health effects; however, whether air pollution is associated with urological cancer is largely unknown. We conduct a systematic review and meta-analysis with epidemiological studies, showing that a 5 μg/m3 increase in PM2.5 exposure is associated with a 6%, 7%, and 9%, increased risk of overall urological, bladder, and kidney cancer, respectively; and a 10 μg/m3 increase in NO2 is linked to a 3%, 4%, and 4% higher risk of overall urological, bladder, and prostate cancer, respectively. Were these associations to reflect causal relationships, lowering PM2.5 levels to 5.8 μg/m3 could reduce the age-standardized rate of urological cancer by 1.5 ~ 27/100,000 across the 15 countries with the highest PM2.5 level from the top 30 countries with the highest urological cancer burden. Implementing global health policies that can improve air quality could potentially reduce the risk of urologic cancer and alleviate its burden.

The association between trace metals in both cancerous and non-cancerous tissues with the risk of liver and gastric cancer progression in northwest China

Liver cancer and gastric cancer have extremely high morbidity and mortality rates worldwide. It is well known that an increase or decrease in trace metals may be associated with the formation and development of a variety of diseases, including cancer. Therefore, this study aimed to evaluate the contents of aluminium (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), selenium (Se), and zinc (Zn) in cancerous liver and gastric tissues, compared to adjacent healthy tissues, and to investigate the relationship between trace metals and cancer progression. During surgery, multiple samples were taken from the cancerous and adjacent healthy tissues of patients with liver and gastric cancer, and trace metal levels within these samples were analysed using inductively coupled plasma mass spectrometry (ICP-MS). We found that concentrations of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn in tissues from patients with liver cancer were significantly lower than those in healthy controls (P < 0.05). Similarly, patients with gastric cancer also showed lower levels of Cd, Co, Cr, Mn, Ni, and Zn-but higher levels of Cu and Se-compared to the controls (P < 0.05). In addition, patients with liver and gastric cancers who had poorly differentiated tumours and positive lymph node metastases showed lower levels of trace metals (P < 0.05), although no significant changes in their concentrations were observed to correlate with sex, age, or body mass index (BMI). Logistic regression, principal component analysis (PCA), Bayesian kernel regression (BKMR), weighted quantile sum (WQS) regression, and quantile-based g computing (qgcomp) models were used to analyse the relationships between trace metal concentrations in liver and gastric cancer tissues and the progression of these cancers. We found that single or mixed trace metal levels were negatively associated with poor differentiation and lymph node metastasis in both liver and gastric cancer, and the posterior inclusion probability (PIP) of each metal showed that Cd contributed the most to poor differentiation and lymph node metastasis in both liver and gastric cancer (all PIP = 1.000). These data help to clarify the relationship between changes in trace metal levels in cancerous liver and gastric tissues and the progression of these cancers. Further research is warranted, however, to fully elucidate the mechanisms and causations underlying these findings.

Long-term cadmium exposure induces epithelial-mesenchymal transition in breast cancer cells by activating CYP1B1-mediated glutamine metabolic reprogramming in BT474 cells and MMTV-Erbb2 mice

Cadmium (Cd) exposure is known to enhance breast cancer (BC) progression. Cd promotes epithelial-mesenchymal transition (EMT) in BC cells, facilitating BC cell aggressiveness and invasion, but the underlying molecular mechanisms are unclear. Hence, transgenic MMTV-Erbb2 mice (6 weeks) were orally administered Cd (3.6 mg/L, approximately equal to 19.64 μΜ) for 23 weeks, and BC cells (BT474 cells) were exposed to Cd (0, 0.1, 1 or 10 μΜ) for 72 h to investigate the effect of Cd exposure on EMT in BC cells. Chronic Cd exposure dramatically expedited tumor metastasis to multiple organs; decreased E-cadherin density; and increased Vimentin, N-cadherin, ZEB1, and Twist density in the tumor tissues of MMTV-Erbb2 mice. Notably, transcriptomic analysis of BC tumors revealed cytochrome P450 1B1 (CYP1B1) as a key factor that regulates EMT progression in Cd-treated MMTV-Erbb2 mice. Moreover, Cd increased CYP1B1 expression in MMTV-Erbb2 mouse BC tumors and in BT474 cells, and CYP1B1 inhibition decreased Cd-induced BC cell malignancy and EMT in BT474 cells. Importantly, the promotion of EMT by CYP1B1 in Cd-treated BC cells was presumably controlled by glutamine metabolism. This study offers novel perspectives into the effect of environmental Cd exposure on driving BC progression and metastasis, and this study provides important guidance for comprehensively assessing the ecological and health risks of Cd.