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Abstract: Rainwater and airborne particles were sampled at five sites, including Beijing and Mazhuang Town in the northeast of China, Chongqing in the southwest of China, Shenzhen and Mangdang Mountain in the south of China. The pollution of airborne particles in winter at Chongqing and Beijing were the worst and the following was in summer at Mazhuang town and atmosphere quality in spring at Mangdang Mountain was the best. The ratios of fine particles to coarse particles were high among all the sampling sites. The contribution from soluble components to particulate mass was important and the main ions both on PM10 and PM2.5 were SO4 2 −, NO3 − and NH4 +. Both inorganic and organic soluble components on particles were mainly enriched on fine particles. The average pH values in rainwater at Beijing, Mazhuang Town, Shenzhen and Mangdang Mountain were 6.02, 5.97, 4.72 and 4.81 respectively. A new methodology to determine the neutralizing capacity of airborne particles was established in this study. The pH values and water-soluble ion concentrations in particulate matter extract were measured, then the ionization balance and charge conservation principle were adopted to determine the amount of acid-basic compositions on particle. The amount of H+ in rainwater neutralized by airborne particles per unit mass was used to denote the neutralizing capacity of particles. The neutralizing capacity of airborne particles was lower if both of the concentrations of particles and ratio of fine to coarse particles were higher. The neutralizing capacity of airborne particles was inverse proportion to the acidity of rainwater and the rain intensity. The neutralizing effect of particles accounted for 4%–28% of the reduction of rainwater acidity during wash-out process among different sites, and it was deduced that NH3 was the major neutralizing species especially for rainwater from sites in the northeast of China. [Copyright &y& Elsevier]

Background: Screening for Tuberculosis (TB) is a critical tactic for minimizing the prevalence of illness within schools. Tuberculosis Preventive Therapy (TPT), in turn, effectively staves off the development of TB from latent tuberculosis infection (LTBI). Unfortunately, there is limited research on LTBI and TPT among students. This study aimed to assess LTBI among freshmen in Changping District and advocate for the implementation of TPT. Methods: The prospective study collected data from 12 educational institutions within the Changping District of Beijing. The Kolmogorov − Smirnov test and other statistical methods were used for statistical analysis, x 2 was obtained using the formula x 2 = nΣA2/nRnC-1, df = (C-1) (R-1). We analyzed potential factors impacting the LTBI rate, and scrutinized the possible causes behind the low application of TPT and its efficacy for LTBI treatment, China. Results: Among 19,872 freshmen included in this study, 18 active TB cases (91 per 10,0000) and 2236 LTBI cases (11.6% of 19,223) were identified, respectively. Furthermore, of those with LTBI, 1045 (5.4% of 19,223) showed a strong positive for purified protein derivative (PPD), but only 312 opted for TB preventive treatment. There appeared to be no significant difference in the prevalence of LTBI and TPT rate between male and female students. Concurrently, 11 (71 per 100,000) and 7 (158 per 100,000) cases of active tuberculosis were identified in 6 universities and 6 higher vocational colleges, respectively. Interestingly, almost all freshmen who underwent TPT came from universities, suggesting a statistically significant disparity in TPT rate (χ2 = 139.829, P < 0.001) between these two types of educational institutions. Meanwhile, as for the age-wise distribution of latent infection among 17–20 years old freshmen, the LTBI rate exhibited 10.5%, 11.6%, 12.1% and 13.5%, respectively. Correlation between LTBI rate, the strong positive rate was statistically significant among different ages (χ2 = 34.559, P < 0.001). Over a follow-up period of 2 years, three students were diagnosed with active tuberculosis, one of which was resistant to rifampicin. All three students manifested a strong positive for PPD and declined preventive treatment during TB screening. Conclusions: The data indicates a high rate of LTBI amongst students in areas with a heavy TB burden, potentially leading to cross-regional TB transmission due to the migration of students. Education level might contribute to the limited uptake of TPT. Therefore, improving the implementation of TB preventive treatments is crucial in controlling and preventing TB across schools. [ABSTRACT FROM AUTHOR]

Background: Screening for Tuberculosis (TB) is a critical tactic for minimizing the prevalence of illness within schools. Tuberculosis Preventive Therapy (TPT), in turn, effectively staves off the development of TB from latent tuberculosis infection (LTBI). Unfortunately, there is limited research on LTBI and TPT among students. This study aimed to assess LTBI among freshmen in Changping District and advocate for the implementation of TPT. Methods: The prospective study collected data from 12 educational institutions within the Changping District of Beijing. The Kolmogorov − Smirnov test and other statistical methods were used for statistical analysis, x 2 was obtained using the formula x 2 = nΣA2/nRnC-1, df = (C-1) (R-1). We analyzed potential factors impacting the LTBI rate, and scrutinized the possible causes behind the low application of TPT and its efficacy for LTBI treatment, China. Results: Among 19,872 freshmen included in this study, 18 active TB cases (91 per 10,0000) and 2236 LTBI cases (11.6% of 19,223) were identified, respectively. Furthermore, of those with LTBI, 1045 (5.4% of 19,223) showed a strong positive for purified protein derivative (PPD), but only 312 opted for TB preventive treatment. There appeared to be no significant difference in the prevalence of LTBI and TPT rate between male and female students. Concurrently, 11 (71 per 100,000) and 7 (158 per 100,000) cases of active tuberculosis were identified in 6 universities and 6 higher vocational colleges, respectively. Interestingly, almost all freshmen who underwent TPT came from universities, suggesting a statistically significant disparity in TPT rate (χ2 = 139.829, P < 0.001) between these two types of educational institutions. Meanwhile, as for the age-wise distribution of latent infection among 17–20 years old freshmen, the LTBI rate exhibited 10.5%, 11.6%, 12.1% and 13.5%, respectively. Correlation between LTBI rate, the strong positive rate was statistically significant among different ages (χ2 = 34.559, P < 0.001). Over a follow-up period of 2 years, three students were diagnosed with active tuberculosis, one of which was resistant to rifampicin. All three students manifested a strong positive for PPD and declined preventive treatment during TB screening. Conclusions: The data indicates a high rate of LTBI amongst students in areas with a heavy TB burden, potentially leading to cross-regional TB transmission due to the migration of students. Education level might contribute to the limited uptake of TPT. Therefore, improving the implementation of TB preventive treatments is crucial in controlling and preventing TB across schools. [ABSTRACT FROM AUTHOR]