OBJECTIVES: Previous studies have demonstrated that the metals cadmium and arsenic exhibit estrogen-like effects and may influence the occurrence and development of gynecological tumors. This study aims to explore the association between urinary cadmium and arsenic levels and the prevalence of gynecologic cancers using data from the National Health and Nutrition Examination Survey (NHANES). METHODS: Data from female participants in NHANES 2003-2018 were analyzed. Using R software, datasets (DEMO, BMX, etc.) were merged, and complete cases were retained by intersecting row names, yielding a total of 2 999 participants. After applying strict exclusion criteria, 2 802 participants were included: 83 with gynecologic cancer (cancer group) and 2 719 without (control group). Demographic, reproductive health, and urinary cadmium and arsenic data were collected. Binary Logistic regression models were employed to assess associations between urinary cadmium and arsenic levels and gynecologic cancer risk. RESULTS: High urinary cadmium and arsenic levels were risk factors for gynecologic cancers, with odds ratios (ORs) of 1.623 (95% CI 1.217 to 2.166) and 1.003 (95% CI 1.001 to 1.005), respectively. After propensity score matching (PSM), the trend remained; cadmium was still a statistically significant risk factor with an OR of 2.182 (95% CI 1.343 to 3.545), while arsenic's association, though not statistically significant, still trended toward risk (OR=1.004, 95% CI 0.999 to 1.009). Subgroup analyses showed that both cadmium and arsenic were risk factors for ovarian cancer (OR=1.745, 95% CI 1.178 to 2.586 and OR=1.005, 95% CI 1.002 to 1.008, respectively); these associations persisted after PSM. Additionally, cadmium increased the risk of endometrial cancer (OR=1.617, 95% CI 1.109 to 2.356). CONCLUSIONS Exposure to cadmium and arsenic is associated with an increased risk of ovarian and endometrial cancers. These findings suggest that reducing environmental exposure to heavy metals such as cadmium and arsenic may help prevent certain gynecologic cancers.
Humans ; Female ; Cadmium/urine* ; Arsenic/urine* ; Genital Neoplasms, Female/urine* ; Middle Aged ; Nutrition Surveys ; Adult ; Risk Factors ; Environmental Exposure/adverse effects* ; Aged

Objective: To evaluate the preventive effect of implementing the free influenza vaccination policy on school absence among primary and secondary school students, so as to provide a reference for formulating and adjusting vaccination strategies. Methods: Among primary and secondary school students aged 6 to 18 in Longgang District, Shenzhen, they were divided into a vaccinated group (265 996 students) and an unvaccinated group (122 513 students) according to their influenza vaccination history during November 2023. Propensity score matching was used to conduct a 1∶1 match between the two groups to balance covariates. The number of absences per month was set as the dependent variable to construct a difference in differences model, and Poisson regression was employed to analyze the overall and multi time point effects. Results: Vaccination against influenza was associated with low rate of absenteeism among primary and secondary school students, with an overall preventive effect of 26.52% (95% CI = 23.47% -29.45%). The preventive effects in November (the month of vaccination) and December 2023, January and March 2024 were 42.12%, 40.12%, 30.33% and 20.91%, respectively. The preventive effect of the influenza vaccine on absenteeism among primary school students (26.39%) was not significantly different from that among secondary school students ( 27.97% ) ( P >0.05). The regression coefficient for class vaccination rates ranged from 0.998 to 0.999 ( P <0.01), indicating that for every 10% increase in influenza vaccination rates, absenteeism could be reduced by 1.5% to 2.2%. Conclusion Implementing free influenza vaccination for primary and secondary school students might help to reduce the risk of absenteeism, yielding significant socioeconomic benefits.