The burden of disease attributable to indoor air pollutants in China from 2000 to 2017.

BACKGROUND: High-level exposure to indoor air pollutants (IAPs) and their corresponding adverse health effects have become a public concern in China in the past 10 years. However, neither national nor provincial level burden of disease attributable to multiple IAPs has been reported for China. This is the first study to estimate and rank the annual burden of disease and the financial costs attributable to targeted residential IAPs at the national and provincial level in China from 2000 to 2017. METHODS: We first did a systematic review and meta-analysis of 117 articles from 37 231 articles identified in major databases, and obtained exposure-response relationships for the candidate IAPs. The exposure levels to these IAPs were then collected by another systematic review of 1864 articles selected from 52 351 articles. After the systematic review, ten IAPs with significant and robust exposure-response relationships and sufficient exposure data were finally targeted: PM2·5, nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide, radon, formaldehyde, benzene, toluene, and p-dichlorobenzene. The annual exposure levels in residences were then evaluated in all 31 provinces in mainland China continuously from 2000 to 2017, using the spatiotemporal Gaussian process regression model to analyse indoor originating IAPs, and the infiltration factor method to analyse outdoor originating IAPs. The disability-adjusted life-years (DALYs) attributable to the targeted IAPs were estimated at both national and provincial levels in China, using the population attributable fraction method. Financial costs were estimated by an adapted human capital approach. FINDINGS: From 2000 to 2017, annual DALYs attributable to the ten IAPs in mainland China decreased from 4620 (95% CI 4070-5040) to 3700 (3210-4090) per 100 000. Nevertheless, in 2017, IAPs still ranked third among all risk factors, and their DALYs and financial costs accounted for 14·1% (95% CI 12·3-15·6) of total DALYs and 3·45% (3·01-3·82) of the gross domestic product. Specifically, the rank of ten targeted IAPs in order of their contribution to DALYs in 2017 was PM2·5, carbon monoxide, radon, benzene, nitrogen dioxide, ozone, sulphur dioxide, formaldehyde, toluene, and p-dichlorobenzene. The DALYs attributable to IAPs were 9·50% higher than those attributable to outdoor air pollution in 2017. For the leading IAP, PM2·5, the DALYs attributable to indoor origins are 18·3% higher than those of outdoor origins. INTERPRETATION: DALYs attributed to IAPs in China have decreased by 20·0% over the past two decades. Even so, they are still much higher than those in the USA and European countries. This study can provide a basis for determining which IAPs to target in various indoor air quality standards and for estimating the health and economic benefits of various indoor air quality control approaches, which will help to reduce the adverse health effects of IAPs in China. FUNDING: The National Key Research and Development Program of China and the National Natural Science Foundation of China.

Health effects of exposure to sulfur dioxide, nitrogen dioxide, ozone, and carbon monoxide between 1980 and 2019: A systematic review and meta-analysis.

The burden of disease attributed to the indoor exposure to sulfur dioxide (SO2 ), nitrogen dioxide (NO2 ), ozone (O3 ), and carbon monoxide (CO) is not clear, and the quantitative concentration-response relationship is a prerequisite. This is a systematic review to summarize the quantitative concentration-response relationships by screening and analyzing the polled effects of population-based epidemiological studies. After collecting literature published between 1980 and 2019, a total of 19 health outcomes in 101 studies with 182 health risk estimates were recruited. By meta-analysis, the leave-one-out sensitivity analysis and Egger's test for publication bias, the robust and reliable effects were found for SO2 (per 10 µg/m3 ) with chronic obstructive pulmonary diseases (COPD) (pooled relative risks [RRs] 1.016, 95% CI: 1.012-1.021) and cardiovascular diseases (CVD) (RR 1.012, 95%CI: 007-1.018), respectively. NO2 (per 10 µg/m3 ) had the pooled RRs for childhood asthma, preterm birth, lung cancer, diabetes, and COPD by 1.134 (1.084-1.186), 1.079 (1.007-1.157), 1.055 (1.010-1.101), 1.019 (1.009-1.029), and 1.016 (1.012-1.120), respectively. CO (per 1 mg/m3 ) was significantly associated with Parkinson's disease (RR 1.574, 95% CI: 1.069-2.317) and CVD (RR 1.024, 95% CI: 1.011-1.038). No robust effects were observed for O3 . This study provided evidence and basis for further estimation of the health burden attributable to the four gaseous pollutants.

Epidemiological and clinical features of SARS-CoV-2 cluster infection in Anhui Province, Eastern China.

BACKGROUND: COVID-19 has spread worldwide and become a pandemic. We report the epidemiological and clinical characteristics of cluster infections. METHODS: Data of clustered cases were retrieved from the public health emergency monitoring information system of China. We analyzed the incubation period, generation gap, secondary attack rate, and viral load in various grouped cases. RESULTS: A total of 60 COVID-19 infection clusters including 226 patients and 19 asymptomatic cases involving four generations were analyzed. With the increase of transmission generations, secondary attack rate decreased (P＜0.001) and severity alleviated (P = 0.008). The median incubation period and intergenerational interval were 9 and 6 days, respectively. The secondary attack rate was 7.1% in the index cases, 5.0% in the first generation, 1.0% in the second generation, and 4.7% overall. Severe cases were seen more in the index (13, 65%) and first generation (7, 35%) ones, who had a significantly higher viral load than the mild and moderate ones. CONCLUSIONS: With the increase of transmission generation, secondary infection rate and severity decreased. Severe patients had a higher virus load. Patients in the incubation period and asymptomatic carriers were potential infection sources who might play an important role in transmission.

[The role of nasal nitric oxide in diagnosis and endotypes of chronic rhinosinusitis with nasal polyp].

Objective:To investigate the roles of nasal nitric oxide（nNO） in diagnosis and endotypes of CRSwNP. Methods:Eighty-two CRSwNP patients and thirty healthy volunteers were recruited for this study. The patients were classified into eosinophilic CRSwNP （Eos CRSwNP） and non-eosinophilic CRSwNP （non-Eos CRSwNP） endotypes by tissue eosinophil percentage. nNO levels were measured with an electrochemical sensor-based device. nNO levels and clinical factors were compared among the groups. Receiver-operating characteristic （ROC） curve and logistic regression analyses were performed to evaluate the predictive ability of the nNO for diagnosis and endotypes of CRSwNP. Results:Eos CRSwNP patients（143.9±106.2） ×10-9 had lower nNO levels than non-Eos CRSwNP[（228.3±109.2） ×10-9, P=0.000 9） and healthy subjects（366.5±88.0） ×10-9, P<0.000 1）. Patients with atopy exhibited significantly higher levers of nNO compared with patients without atopy（P<0.05）. For Eos CRSwNP diagnosis, nNO had the highest predictive value（AUC: 0.939; sensitivity: 76.74%; specificity: 96.67%; cut-off value: 231×10-9, P<0.001）. Furthermore, nNO levels were associated with CRSwNP endotypes（odds ratio: 1.010; 95% confidence interval: 1.003%, 1.016%; P=0.002）. When the nNO concentration was 158 ×10-9, we could discriminate Eos CRSwNP from non-Eos CRSwNP（AUC=0.710, sensitivity: 76.92%; specificity, 60.47%, P=0.001）. After it was combinated by nNO, periphera blood eosinophil count（PEAC） and VAS score, the AUC was increased to 0.894（95%CI=0.807 to 0.951, P<0.000 1, sensitivity: 76.74%, specificity: 89.74%）. Conclusion:nNO may has potential for non-invasive diagnosis and endotype of CRSwNP. nNO combined with PEAC and VAS score may be an ideal diagnostic tool for endotyps of Eos CRSwNP. However, the atopic status of the patients influenced the levels of nNO.

The roles of nasal nitric oxide in diagnosis and endotypes of chronic rhinosinusitis with nasal polyps.

BACKGROUND: Chronic rhinosinusitis with polyps (CRSwNP) is a global health concern. Nasal nitric oxide (nNO), a clinical biomarker, have been studied to assess the presence of airway mucosal inflammation. This study aimed to clarify the roles of nNO in diagnosis and endotypes of CRSwNP. METHODS: Eighty-two CRSwNP patients and thirty healthy volunteers were recruited for this study. The patients were classified into eosinophilic CRSwNP (Eos CRSwNP) and non⁃eosinophilic CRSwNP (Non-Eos CRSwNP) endotypes by tissue eosinophil percentage. nNO levels were measured with an electrochemical sensor-based device. nNO levels and clinical factors were compared among the groups. Receiver-operating characteristic (ROC) curve and logistic regression analyses were performed to evaluate the predictive ability of the nNO for diagnosis and endotypes of CRSwNP. RESULTS: Eos CRSwNP patients(143.9 ± 106.2, ppb) had lower nNO levels than Non-Eos CRSwNP(228.3 ± 109.2, ppb, p = 0.013) and healthy subjects(366.5 ± 88, ppb, p < 0.0001). Patients with atopy exhibited significantly higher levers of nNO compared with patients without atopy (p < 0.05). For Eos CRSwNP diagnosis, nNO had high predictive value for Eos CRSwNP (AUC: 0.939; sensitivity: 76.74%; specificity: 96.67%; cut-off value: 231 ppb, p < 0.001). Furthermore, nNO levels were associated with CRSwNP endotypes (odds ratio: 1.010; 95% confidence interval: 1.003, 1.016%; p = 0.002). When the nNO concentration was 158 ppb, we could discriminate Eos CRSwNP from Non-Eos CRSwNP (AUC = 0.710, sensitivity: 76.92%; specificity, 60.47%, P = 0.001). After it was combinated by nNO, peripheral blood eosinophil count (PEAC) and VAS score, the AUC was increased to 0.894 (95%CI = 0.807 to 0.951, p < 0.0001, sensitivity:76.74%, specificity: 89.74%). CONCLUSIONS: nNO may have potential for non-invasive diagnosis and endotype of CRSwNP. nNO combined with PEAC and VAS score may be a good diagnostic tool for endotyps of Eos CRSwNP. However, the atopic status of the patients influenced the levels of nNO.

Effects of filtered fresh air ventilation on classroom indoor air and biomarkers in saliva and nasal samples: A randomized crossover intervention study in preschool children.

To evaluate the short-term effects of filtered fresh air ventilation system on classroom indoor air and biomarkers in saliva and nasal samples in preschool children, a randomized crossover study was conducted in a kindergarten in Shanghai, China in 2016. Two classrooms at the same grade (n = 43) were selected and fresh air ventilation systems (FAVS) with high efficiency particulate air filter (HEPA) were installed. In the first week, FAVS-HEPA was run in one classroom for 2 continuous school days and the other classroom was remained as usual with no use of FAVS-HEPA. After one week of wash-out, the ventilation modes exchanged between two classrooms and another 2 days of intervention were repeated. Real-time indoor and outdoor air pollution and climate factors (PM2.5, Temp and relative humidity (R.H.)) were measured. Saliva and nasal internal mucosa samples were collected immediately at the end of each intervention scenario. Linear mixed-effect regression model was applied to evaluate the effects of intervention on children's health indicators controlling for age, gender, height, BMI and temperature. The results showed, with FAVS-HEPA, the classroom indoor fine particulate matter (PM2.5)(29.1 ±â€¯17.9 µg/m3) was on average significantly lower than that without FAVS-HEPA (85.7 ±â€¯43.2 µg/m3). By regression analysis, each 10 µg/m3 decrease of indoor PM2.5 during the 8 school hours in the first intervention day was associated with an average of 1.76% (95% confidence interval (CI) 0.43-3.08%) increase in saliva lysozyme. This percentage increased to 2.41% (95%CI 0.52-4.26%) if related to the PM2.5 level in 16 school hours over 2 days of intervention. A total of 19 nasal bacterial taxa were lower in subjects exposed to FAVS-HEPA, compared to that with no use of FAVS-HEPA, despite the general bacteria diversity levels in nasal samples were not statistically different. Among others, Providencia species showed significant effects in mediating the associations between higher PM2.5 and lower lysozyme. In conclusion, using FAVS-HEPA was effective in decreasing the classroom indoor PM2.5. Saliva lysozyme, as a non-specific immune biomarker, was significantly inversely associated with indoor PM2.5. Certain nasal bacteria might play key roles in mediating PM2.5 exposure and children's lysozyme levels.

[Cloning and functional validation of promoter of mo-molybdopterin cofactor sulfurase gene in maize].

To overcome the problems caused by the over-expression of exogenous genes under the control of constitutive promoters, the promoter (ABA3s) sequence of maize (Zea mays) mo-molybdopterin cofactor sulfurase gene (ABA3) was cloned homologously, analyzed for its abiotic stress-responsive elements by the PlantCARE software, and detected for differential expression of the ABA3 gene under the abiotic stresses by real-time quantitative PCR. Then, this promoter was used to construct expression vector to start GUS (ß-glucuronidase) gene, and transform maize calli by biolistics. After identification by histochemical staining, the ratio of the GUS activity relative to the luciferase activity (internal control) (GUS/LUC) was measured under the stresses of hypertonic, high salt, low temperature, and the induction of ABA, and used to evaluate the activity of the ABA3s promoter in response to abiotic stresses. The results showed that the ABA3 gene was differentially expressed under the stress of simulative drought, low temperature, high temperature, high salt, and the induction of ABA and ethylene, indicating that the promoter (ABA3s) of this gene is induced by abtiotic stress. The sequence analysis showed that the ABA3s promoter is 777 bp long, and contains abiotic stress-responsive elements ARE, HSE, MBS, TGA and circadian. The transformed calli by the expression vector of the GUS gene under the control of the ABA3s promoter showed positive in GUS detection in response to the abiotic stresses of drought, low temperature, high temperature, high salt, and the induction of ABA and ethylene. The GUS/LUC ratio was six folds higher than the blank control under the hypertonic stress of 8% mannitol. It is concluded that the promoter ABA3s is inducible in response to abiotic stresses, and might be applied to transgenic research of maize for abiotic tolerance after further functional evaluation.