BACKGROUND: Organic chemicals have been known to cause allergic diseases such as bronchial asthma and hypersensitivity pneumonitis; however, the possibility that they do not cause irreversible pulmonary fibrosis has not been considered. Polyacrylic acid (PAA), an organic chemical, has caused irreversible progressive pulmonary fibrosis in exposed workers, indicating its potential to induce pulmonary inflammation and fibrosis. Although intratracheal instillation studies are commonly used for evaluating lung pathology, traditional methods face challenges with chemical substances, particularly nanoparticles, which tend to aggregate in suspension and prevent uniform pulmonary distribution. Such aggregation alters the qualitative and quantitative responses to lung injury, limiting accurate assessment of lung pathology. To overcome this limitation, we developed a 'molecular dispersion method' that uses pH modification to negative charges to PAA particles, maintaining their dispersion. Using this method, we investigated the effects of PAA on pulmonary inflammation and fibrosis in a rat model. METHODS: F344 rats were intratracheally instilled with PAA using molecular dispersion (0.1 mg/rat, 1.0 mg/rat), PAA without molecular dispersion (1.0 mg/rat), and normal saline (control group). Rats were sacrificed at 3 days, 1 week, 1 month, 3 months, and 6 months after exposure to examine inflammatory and fibrotic responses. RESULTS: PAA caused persistent increases in neutrophil influx in the bronchoalveolar lavage fluid (BALF) from 3 days to 1 month following instillation. In histopathological findings, the group with molecular dispersion had almost no inflammatory masses in the lung tissue compared to the group without molecular dispersion, and exhibited relatively uniform dispersion. CONCLUSION Intratracheal instillation of dispersed PAA induced neutrophil inflammation and fibrosis in the rat lung, suggesting that PAA might have pulmonary inflammogenicity and fibrogenicity. Intrapulmonary dispersion of PAA particles following intratracheal instillation studies using the molecular dispersion method was similar to that following inhalation studies.
Animals ; Rats, Inbred F344 ; Acrylic Resins/adverse effects* ; Rats ; Inhalation Exposure/adverse effects* ; Male ; Pulmonary Fibrosis/pathology* ; Pneumonia/pathology* ; Lung/pathology* ; Bronchoalveolar Lavage Fluid/cytology*

OBJECTIVES: Due to prolonged exposure to cosmic radiation and meteorite impacts, lunar surface dust forms nanoscale angular particles with strong electrostatic adsorption properties. These dust particles pose potential inhalation risks, yet their pulmonary toxicological mechanisms remain unclear. Given the need for dust exposure protection in future lunar base construction and resource development, this study established an acute exposure model using lunar soil simulant (LSS) and used Earth soil (ES; Loess from Shaanxi, China) as a comparison to investigate lung injury mechanisms. METHODS: C57BL/6 mice were randomly assigned to 3 groups: Phosphate buffered saline (PBS), LSS, and ES, with 5 to 7 mice per group. Mice in the LSS and ES groups received a single intratracheal instillation to induce acute inhalation exposure. Body weight was monitored for 28 days. Mice were euthanized at days 3, 7, 14, and 28 post-exposure, and peripheral blood, bronchoalveolar lavage fluid (BALF), and lung tissues were collected. Immune cell subsets in BALF were analyzed using flow cytometry. Hematoxylin-eosin (HE) staining assessed lung structure and inflammation; periodic acid-Schiff (PAS) staining evaluated airway mucus secretion; Masson staining examined collagen deposition. Real-time reverse transcription PCR (real-time RT-PCR) was used to measure the mRNA expression of inflammatory cytokines (IL-1β, IL-6, and TNF-α) and epithelial barrier genes (Occludin, Cadherin-1, and Zo-1). Lung tissues at day 7 were subjected to transcriptomic sequencing, followed by immune infiltration and pathway enrichment analyses to determine immunoregulatory mechanisms. RESULTS: Body weight in the ES group progressively declined after day 18 (all P<0.05), while the LSS group showed no significant changes compared with the control group. HE staining showed both LSS and ES induced inflammatory cell infiltration around airways and vasculature, which persisted for 28 days but gradually lessened over time. PAS staining revealed marked mucus hypersecretion in the LSS group at day 3, followed by gradual recovery; no significant mucus changes were observed in the ES group. Masson staining indicated no obvious pulmonary fibrosis in either group within 28 days. Real-time RT-PCR demonstrated significant upregulation of IL-1β and TNF-α in both LSS and ES groups, peaking on day 7, accompanied by downregulation of epithelial barrier genes (Occludin, Cadherin-1, and Zo-1)(all P<0.05). Transcriptomic analysis showed that both LSS and ES activated chemokine-related pathways and enriched leukocyte migration and neutrophil recruitment pathways. Further validation revealed upregulation of CXCL2 and MMP12 in the LSS group, whereas CXCL3 and MMP12 were predominantly elevated in the ES group. CONCLUSIONS Both LSS and ES can induce sustained lung injury and neutrophil infiltration in mice, though the underlying molecular mechanisms differ. Compared with ES, exposure to LSS additionally triggers a transient eosinophilic response, suggesting that lunar dust particles possess stronger immunostimulatory potential and higher biological toxicity.
Animals ; Mice ; Mice, Inbred C57BL ; Soil ; Lung Injury/etiology* ; Dust ; Bronchoalveolar Lavage Fluid ; Moon ; Lung/pathology* ; Inhalation Exposure/adverse effects* ; Male

BACKGROUND: We previously demonstrated that continuous exposure to nitrous acid gas (HONO) for 4 weeks, at a concentration of 3.6 parts per million (ppm), induced pulmonary emphysema-like alterations in guinea pigs. In addition, we found that HONO affected asthma symptoms, based on the measurement of respiratory function in rats exposed to 5.8 ppm HONO. This study aimed to investigate the dose-response effects of HONO exposure on the histopathological alterations in the respiratory tract of guinea pigs to determine the lowest observed adverse effect level (LOAEL) of HONO. METHODS: We continuously exposed male Hartley guinea pigs (n = 5) to four different concentrations of HONO (0.0, 0.1, 0.4, and 1.7 ppm) for 4 weeks (24 h/day). We performed histopathological analysis by observing lung tissue samples. We examined samples from three guinea pigs in each group under a light microscope and measured the alveolar mean linear intercept (Lm) and the thickness of the bronchial smooth muscle layer. We further examined samples from two guinea pigs in each group under a scanning electron microscope (SEM) and a transmission electron microscope (TEM). RESULTS: We observed the following dose-dependent changes: pulmonary emphysema-like alterations in the centriacinar regions of alveolar ducts, significant increase in Lm in the 1.7 ppm HONO-exposure group, tendency for hyperplasia and pseudostratification of bronchial epithelial cells, and extension of the bronchial epithelial cells and smooth muscle cells in the alveolar duct regions. CONCLUSIONS These histopathological findings suggest that the LOAEL of HONO is < 0.1 ppm.
Alveolar Epithelial Cells ; drug effects ; Animals ; Bronchi ; drug effects ; Dose-Response Relationship, Drug ; Emphysema ; chemically induced ; Epithelial Cells ; drug effects ; Guinea Pigs ; Hyperplasia ; chemically induced ; Inhalation Exposure ; adverse effects ; Lung ; drug effects ; pathology ; ultrastructure ; Male ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Myocytes, Smooth Muscle ; drug effects ; Nitrous Acid ; toxicity

BACKGROUND: Although lead neurotoxicity is a known phenomenon, it can often be missed at a primary or secondary care level especially if detailed environmental exposure history is missed. METHODS: This is an outbreak investigation where we observed 15 pediatric cases with neurologic signs and symptoms clustered in a slum area known for an unorganized artificial jewelry industry. Their clinical, biochemical, and epidemiological features were compared with 14 other children from the same region reporting with non-neurological symptoms who were considered as unmatched controls. RESULTS: Cases with neurological manifestations had a higher in-house lead smelting activity [OR 7.2 (95% CI 1.4-38.3)] as compared to controls. Toddlers below 3 years of age were more vulnerable to the effects of lead. CONCLUSION This study emphasizes that many focal sources of lead poisoning still remain especially in the unorganized sector. In cases presenting with unexplained neurotoxicity, specific occupational and environmental inquiry for chemical poisoning, with special consideration for lead, should be actively pursued.
Adolescent ; Air Pollution, Indoor ; adverse effects ; Case-Control Studies ; Child ; Child, Preschool ; Disease Outbreaks ; Female ; Humans ; India ; epidemiology ; Infant ; Inhalation Exposure ; adverse effects ; Jewelry ; poisoning ; Lead ; blood ; standards ; Lead Poisoning ; epidemiology ; pathology ; physiopathology ; Male ; Metallurgy ; Neurotoxicity Syndromes ; epidemiology ; pathology ; physiopathology ; Poverty Areas ; Risk Factors

Objective: The number of children with polydactyly is increasing. In addition to genetic factors, an influence of maternal behavior or environmental effects during pregnancy is becoming increasingly apparent. However, epidemiological data on these effects are lacking. Methods: This hospital-based, case-control study enrolled 143 infants with polydactyly and 286 controls without genetic diseases to evaluate the association between active and passive maternal smoking during pregnancy and the likelihood of giving birth to a child with polydactyly. Results: Active and passive maternal smoking during pregnancy was associated with an increased risk of giving birth to a child with polydactyly (active smoking: OR=4.74, 95%CI: 1.43-15.65, P=0.011; passive smoking: OR=2.42, 95%CI: 1.32-4.44, P=0.004). After adjusting for confounders, smoking during pregnancy remained significant influence on polydactyly (active smoking: aOR=7.27, 95%CI: 1.72-30.72, P=0.007; passive smoking: aOR=2.41, 95%CI: 1.11-5.23, P=0.026). Conclusion: Active and passive maternal smoking during pregnancy appears to be a risk factor for polydactyly in newborns.
Case-Control Studies ; Child ; Female ; Fingers/abnormalities* ; Humans ; Infant ; Infant, Newborn ; Inhalation Exposure/statistics & numerical data* ; Maternal Exposure/statistics & numerical data* ; Polydactyly/epidemiology* ; Pregnancy ; Pregnancy Complications/etiology* ; Risk Factors ; Smoking/adverse effects* ; Tobacco Smoke Pollution/statistics & numerical data*

OBJECTIVETo investigate whether inhalable particulate matters can cause the damage of chromosome or mitotic apparatus to produce micronucleus, and to evaluate genetic toxicology of moxa smoke on chromosome.

METHODSBy MTT method, the 24 h half maximal inhibitory concentration (IC50) of moxa smoke condensation (MSC) on Chinese hamster ovary (CHO) cells was 0.087 mg/mL. CHO cells, which were cultured in vitro, were divided into a solvent control group, a positive control group (cyclophosphamide as solvent), a low concentration group, a moderate concentration group and a high concentration group. The low concentration group, moderate concentration group and high concentration group were set approximately 1/8, 1/4, 1/2 of IC50, respectively. Whether micronucleus had dose-effect response induced by the damage of chromosome or mitotic apparatus was observed after CHO cells were contaminated by MSC in the low concentration group, moderate concentration group and high concentration group.

RESULTSThe rate of micronucleus induced by MSC in the low concentration group, moderate concentration group and high concentration group was higher than that in the solvent control group (all P < 0.05), which presented dosage-effect response. The experiment was repeated 3 times, indicating it was repeatable with statistical significance.

CONCLUSIONHigh concentration of MSC shows toxicity to induce chromosome damage, which disappears at low concentration. The genetic toxicology is also dependent on concentration, and the concentration of moxa smoke is essential. In clinical treatment, it is noted to control the level of moxa smoke, while the clinical safety standard of moxa smoke concentration is in need of further study.

Air Pollutants ; adverse effects ; Animals ; CHO Cells ; Cell Nucleus ; drug effects ; genetics ; Cricetinae ; Cricetulus ; Inhalation Exposure ; adverse effects ; analysis ; Micronucleus Tests ; Moxibustion ; adverse effects ; Particulate Matter ; adverse effects ; Smoke ; adverse effects ; analysis

Ammonia is commonly used in industry and agriculture. It is also one of the most frequently accidentally spilled chemicals. Exposure to ammonia can cause severe cutaneous burn or freezing injury, ocular injury, and inhalation injury, among them inhalation injury is the most lethal one. Although the diagnosis and treatment of ammonia burns have been improved, the long-term prognosis is not satisfactory. In this article, we reviewed the literature concerning ammonia burns, in order to summarize the clinical features and treatment of such injury.
Ammonia ; adverse effects ; Burns, Chemical ; etiology ; physiopathology ; therapy ; Burns, Inhalation ; Humans ; Inhalation Exposure ; adverse effects ; Prognosis

OBJECTIVE: To observe the effect of formaldehyde inhalation on the allergic rhinitis mice model. METHOD: Forty-eight male BALB/C mice in six experimental group were exposure to (A) saline control; (B) Der p1; (C) formaldehyde (3.0 mg/m3); (D) Derp1 + formaldehyde (1.5 mg/m3); (E) Der p1 + formaldehyde (3.0 mg/M3); (F) Der p1+ formaldehyde (6.0 mg/m3). The concentrations of IL-4, IL-10 and IFN-γ in the peripheral serum were measured by enzyme-linked immunosorbent assay(ELISA). Nasal mucosal inflammation was evaluated by HE staining. Result: Formaldehyde exposure could increase the number of allergic rhinitis mice with sneezing and rubbing nose. The levels of IL-4 and IL-10 in group B, D, E and F were higher than that ingroup A (P < 0.05). Compared with the group C, the group D, E and F could effectively increase serum IL-4 and IL-10. The concentration of IL-4 in group E and F was higher than that of group B, while the group C was lower (P < 0.05). The concentration of IL-10 in group D, E and F was higher than that in group B (P < 0.05). The expression of IFN-γ in group B, D, E and F was lower than that in group A. While, the IFN-γ expression in group B was lower than that of group C and higher than that in group F (P < 0.05). Moreover, the concentration of IFN-γ in group D, E and F was lower compared with group C (P < 0.05). The nasal mucosa HE staining showed that the density of EOS increased simultaneously in formaldehyde exposure allergic rhinitis groups. CONCLUSION The study showed that formaldehyde exposure can promote Th2 cytokines and eosinophil infiltration and then aggravate the allergic rhinitis symptoms.
Animals ; Antigens, Dermatophagoides ; Arthropod Proteins ; Cysteine Endopeptidases ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Formaldehyde ; adverse effects ; Inflammation ; Inhalation Exposure ; adverse effects ; Interferon-gamma ; blood ; Interleukin-10 ; blood ; Interleukin-4 ; blood ; Male ; Mice ; Mice, Inbred BALB C ; Nasal Mucosa ; Rhinitis, Allergic ; chemically induced

BACKGROUND/AIMS: Although indoor air pollution is a well-known risk factor for tuberculosis (TB), the possible link between outdoor air pollution and TB development has not been examined fully. We assessed the impact of outdoor air pollution on TB development in the Seoul metropolitan area, South Korea. METHODS: The mean concentrations of ambient particulate matter (PM) with an aerodynamic diameter < or = 10 microm (PM10), O3, CO, NO2, and SO2 levels in Seoul, between January 1, 1997 and December 31, 2006, were determined. Furthermore, their association with the risk of developing TB after adjusting for socioeconomic status, between January 1, 2002 and December 31, 2006, was investigated. RESULTS: Between January 1, 2002 and December 31, 2006, a total of 41,185 TB cases were reported in Seoul. Concentrations of PM10, O3, CO, and NO2 were not associated with TB incidence in males or females. However, the interquartile increase in SO2 concentration was associated with a 7% increment in TB incidence (relative risk [RR], 1.07; 95% credible interval [CrI], 1.03 to 1.12) in males but not in females (RR, 1.02; 95% CrI, 0.98 to 1.07). CONCLUSIONS: Long-term exposure to ambient SO2 increased the risk of TB in males.
Adult ; Aged ; Air Pollution, Indoor/*adverse effects ; Female ; Humans ; Incidence ; Inhalation Exposure/adverse effects ; Male ; Middle Aged ; Odds Ratio ; Particle Size ; Particulate Matter/adverse effects ; Republic of Korea/epidemiology ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Sex Factors ; Sulfur Dioxide/*adverse effects ; Time Factors ; Tuberculosis, Pulmonary/diagnosis/*epidemiology/microbiology ; *Urban Health

Gaseous molecules continue to hold new promise in molecular medicine as experimental and clinical therapeutics. The low molecular weight gas carbon monoxide (CO), and similar gaseous molecules (e.g., H2S, nitric oxide) have been implicated as potential inhalation therapies in inflammatory diseases. At high concentration, CO represents a toxic inhalation hazard, and is a common component of air pollution. CO is also produced endogenously as a product of heme degradation catalyzed by heme oxygenase enzymes. CO binds avidly to hemoglobin, causing hypoxemia and decreased oxygen delivery to tissues at high concentrations. At physiological concentrations, CO may have endogenous roles as a signal transduction molecule in the regulation of neural and vascular function and cellular homeostasis. CO has been demonstrated to act as an effective anti-inflammatory agent in preclinical animal models of inflammation, acute lung injury, sepsis, ischemia/reperfusion injury, and organ transplantation. Additional experimental indications for this gas include pulmonary fibrosis, pulmonary hypertension, metabolic diseases, and preeclampsia. The development of chemical CO releasing compounds constitutes a novel pharmaceutical approach to CO delivery with demonstrated effectiveness in sepsis models. Current and pending clinical evaluation will determine the usefulness of this gas as a therapeutic in human disease.
Administration, Inhalation ; Animals ; Anti-Inflammatory Agents/administration & dosage/adverse effects/metabolism/*therapeutic use ; Carbon Monoxide/administration & dosage/adverse effects/metabolism/*therapeutic use ; Dose-Response Relationship, Drug ; Environmental Pollutants/adverse effects ; Gases ; Heme/metabolism ; Heme Oxygenase (Decyclizing)/metabolism ; Humans ; Inhalation Exposure/adverse effects ; Risk Assessment ; Signal Transduction