Control priority based on source-specific DALYs of PM2.5-bound heavy metals by PMF-PSCF-IsoSource model in urban and suburban Beijing.

To determine the priority control sources, an approach was proposed to evaluate the source-specific contribution to health risks from inhaling PM2.5-bound heavy metals (PBHMs). A total of 482 daily PM2.5 samples were collected from urban and suburban areas of Beijing, China, between 2018 and 2019. In addition to the PMF-PSCF model, a Pb isotopic IsoSource model was built for more reliable source apportionment. By using the comprehensive indicator of disability-adjusted life years (DALYs), carcinogenic and noncarcinogenic health risks could be compared on a unified scale. The study found that the annual average concentrations of the total PBHMs were significantly higher in suburban areas than in urban areas, with significantly higher concentrations during the heating season than during the nonheating season. Comprehensive dust accounted for the largest contribution to the concentration of PBHMs, while coal combustion contributed the most to the DALYs associated with PBHMs. These results suggest that prioritizing the control of coal combustion could effectively reduce the disease burden associated with PBHMs, leading to notable public health benefits.

Penile skin lesions and urinary tract obstruction: A rare presentation of Langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) can manifest in any organ or system, but the occurrence of cutaneous lesions on the penis, causing urethral stenosis, is particularly uncommon. The diagnosis primarily relies on typical clinical manifestations and pathological examination. Treatment involves the excision of local lesions combined with chemotherapy, with a generally favorable prognosis. A 3-year-old male patient experienced voiding difficulties after circumcision, revealing penile skin lesions upon examination. Postoperative pathological analysis and immunohistochemistry confirmed the diagnosis of LCH. Langerhans cell histiocytosis can present as cutaneous lesions on the penis, leading to symptoms of urinary tract obstruction.

Recommendations for the reference concentration of cadmium exposure based on a physiologically based toxicokinetic model integrated with a human respiratory tract model.

Cadmium (Cd) poses a significant threat to human health. However, chronic toxicity parameters for inhalation exposure are lacking, especially for noncritical systemic toxic effects. A physiologically based toxicokinetic (PBTK) model can be used to extrapolate toxicity parameters across various exposure routes. We combined a PBTK model with a human respiratory tract (HRT) model, which is applicable to the general population and capable of simulating the deposition and clearance processes of various airborne Cd compounds in the respiratory tract. Monte Carlo analysis was used to simulate the distribution of sensitive parameters to reflect individual variability. Validation based on datasets from general and occupational populations showed that the improved model had acceptable or better predictive performance, outperforming the original model with a 14.45 % decrease in the root mean square error (RMSE). Using this PBTK-HRT model, we extrapolated toxicity parameters from oral exposure to inhalation exposure for four systemic toxic effects with doseresponse relationships but no known inhalation toxicity parameters, and ultimately recommended reference concentrations (RfCs) for four diseases (chronic kidney disease: 0.01 µg/m3, osteoporosis: 0.01 µg/m3, stroke: 0.04 µg/m3, diabetes mellitus: 0.13 µg/m3), contributing to a comprehensive assessment of the health risks of Cd inhalation exposure. ENVIRONMENTAL IMPLICATION: Cadmium (Cd), a heavy metal, can cause lung cancer, chronic kidney disease, and osteoporosis and pose a significant threat to human health. We combined a physiologically based toxicokinetic (PBTK) model with a human respiratory tract (HRT) model to achieve better predictive performance and wider applicability; this model was subsequently employed for route-to-route extrapolation of toxicity parameters. Additionally, for the first time, we focused on multiple subchronic and chronic systemic toxic effects in addition to critical effects and derived their reference concentrations (RfCs), which can be used to assess the health risk of Cd inhalation exposure more comprehensively and accurately.