Effects of long-term exposure to ambient PM2.5 on hypertension and role of dietary regulation / 环境与职业医学

Background The contribution of long-term ambient PM2.5 exposure to hypertension should not be ignored. However, the conclusions of whether dietary factors play a role in regulating PM2.5-related hypertension are still inconsistent. Objective To explore the correlation between long-term exposure to ambient PM2.5 and blood pressure indicators (systolic blood pressure, diastolic blood pressure, mean arterial pressure, and pulse pressure) in adults in Ningxia and a potential moderating effect of dietary factors. Methods A set of cross-sectional survey data from March, 2013 to May, 2018 was retrieved from the China Northwest Cohort-Ningxia, and the average ambient PM2.5 concentration in the previous three years was also collected to estimate the long-term exposure of the participants. Binary logistic regression model was used to validate the correlation between long-term exposure to ambient PM2.5 and hypertension in Ningxia, and linear model was used to study the correlation between long-term exposure to ambient PM2.5 and blood pressure indicators (systolic blood pressure, diastolic blood pressure, mean arterial pressure and pulse pressure), and to explore the influence of dietary factors on ambient PM2.5-related hypertension. Results A total of 11470 participants were included in the study, 42.2% male and 57.8% female. The three-year average ambient PM2.5 concentration before the baseline survey was 37.0 μg·m−3. Each 1 μg·m−3 increase in ambient PM2.5 was associated with an increased risk of hypertension (OR=1.111, 95%CI: 1.097, 1.125), and increased systolic blood pressure, diastolic blood pressure, mean arterial pressure, and pulse pressure by 0.886 (95%CI: 0.783, 0.990), 0.570 (95%CI: 0.500, 0.641), 0.676 (95%CI: 0.600, 0.751), and 0.316 (95%CI: 0.243, 0.389) mmHg, respectively. The stratified analysis showed that the OR and 95%CI of hypertension were 1.171 (1.097, 1.254), 1.117 (1.064, 1.174), and 1.160 (1.116, 1.207) respectively for each 1 μg·m−3 increased in PM2.5 with low frequency of vegetable and fruit consumption and salty taste respectively. The OR and 95%CI of hypertension were decreased when the moderate and high frequency of vegetable and fruit intake and moderate and light taste applied, the values were 1.091 (1.062, 1.121) and 1.114 (1.097, 1.131), 1.105 (1.082, 1.129) and 1.111 (1.092, 1.13), 1.115 (1.090, 1.140) and 1.102 (1.083, 1.121) respectively. Compared with low frequency of vegetable and fruit intake and salty taste, the increase degree of ambient PM2.5 related systolic blood pressure, diastolic blood pressure, mean arterial pressure and pulse pressure also decreased in middle and high frequency of vegetable and fruit intake and moderate and light taste. Conclusion Long-term exposure to ambient PM2.5 is significantly associated with increased risks of hypertension and blood pressure in Ningxia area. Increasing the frequency of vegetable and fruit intake and decreasing salty taste may reduce the effect of ambient PM2.5 on hypertension and blood pressure.

Research progress in health effects of long-term exposure to low-dose ionizing radiation / 中国辐射卫生

With the development of nuclear energy and the wide application of ionizing radiation, more and more occupational populations and the public are exposed to low-dose ionizing radiation. Consequently, the research on human health effects of exposure to low-dose ionizing radiation, including carcinogenic and non-carcinogenic effects, have become a hot topic in the field of public health. The biological effects caused by low-dose ionizing radiation mainly depend on the physical property, duration, dose, and dose rate of ionizing radiation. At present, there is no consensus on the effects of long-term exposure to low-dose ionizing radiation on human health. This article reviews the research on the health effects of long-term exposure to low-dose ionizing radiation at home and abroad, and provides a scientific basis for research on the health effects, influence mechanism, and protection strategies of long-term exposure to low-dose ionizing radiation.

Recent advances in health hazards of long-term exposure to microwave radiation / 中国辐射卫生

With the development of the global information technology, electromagnetic equipment such as communication devices and new weapons has been widely deployed. Long-term exposure to electromagnetic radiation causes health hazards to people. Microwave is the most widely used electromagnetic wave. The article reviews the health hazards of long-term exposure to microwave radiation, including damages to the nervous, cardiovascular, blood, reproductive, endocrine, and immune systems and tumorigenesis, and summarizes the possible mechanisms of hazards of long-term exposure to microwave radiation, aiming to provide a theoretical basis for the mechanism study and the research and development of protection technology.

Cardiovascular and Cerebrovascular Diseases Induced by Air Pollution / 中国医学科学院学报

Air pollution has severe detrimental effects on public health.A substantial number of studies have demonstrated that air pollution exposure is a risk factor for the occurrence of cardiovascular and cerebrovascular diseases and a cause of non-communicable diseases.Both long-term and short-term exposure to air pollution are associated with respiratory diseases,stroke,coronary artery disease,and diabetes.Aiming to better understand the association,we reviewed the latest studies about the association of air pollution with cardiovascular and cerebrovascular diseases,especially stroke,coronary heart disease,arrhythmia,hypertension,and heart failure,and summarized the underlying mechanisms of the health damage caused by long-term and short-term exposure to air pollution.

Meta-analysis of effects of long-term exposure to PM2.5 on C-reactive protein levels / 环境与职业医学

Background Fine particulate matter (PM2.5) is a serious air pollutant associated with elevated levels of C-reactive protein (CRP), an inflammatory indicator. Objective To assess the potential impacts of long-term exposure to PM2.5 on CRP levels based on previous epidemiological studies. Methods PubMed, Embase, Web of Science, CNKI, and Wanfang databases were searched to screen the cohort studies published from January 1, 2000 to January 1, 2022 on the effects of long-term exposure to PM2.5 on CRP levels. "Fine Particulate Matter", "PM2.5", "Particulate Air Pollutants", "Ambient Particulate Matter", "CRP", "C-reactive Protein", and "High Sensitivity C-reactive Protein" in English or Chinese were the key words used in the search. The percentage change in CRP level per 10 μg·m−3 increase in PM2.5 concentration in each study was extracted, followed by meta-analysis, subgroup analysis, and sensitivity analysis. Results A total of 1241 articles were retrieved, and 7 articles were included. Random-effects models were used to merge the included data, and it was found that the percentage of CRP level increased by 10.41% (95%CI: 2.24%-18.57%, P<0.05), when PM2.5 concentration increased by 10 μg·m−3, І2=84.2%. The subgroup analysis conducted with grouping based on the annual mean concentration of PM2.5 long-term exposure showed that the intra-group heterogeneity was significantly reduced in the <15 μg·m−3 and the 15- μg·m−3 groups, and the subgroup forest analysis showed differences between the two groups. The results of sensitivity analysis showed that there was a high degree of heterogeneity among the 7 studies, and the 2 papers with the highest annual average PM2.5 concentration were the sources of heterogeneity. The Egger test and the funnel plot indicated that no obvious publication bias was found. Conclusion Long-term exposure to PM2.5 can raise levels of CRP in human body.

Effects of long-term exposure to strong electromagnetic radiation environment on the peripheral complete blood cells of operators / 解放军医学杂志

Objective To observe the effects of long-term exposure to strong electromagnetic environment on the peripheral complete blood cells of the operators. Methods A total of 239 male workers engaged in strong electromagnetic radiation operation for at least 1 year were consecutively raised between April and October 2019 as the exposed group, and 203 male workers no-exposed to strong electromagnetic equipment were raised as non-exposed group. Multipoint measurements were done of electromagnetic frequency and power density in electromagnetic radiation operation area, the differences of blood routine indexes between the exposed group and non-exposed group were compared, and the variation trend of difference index with increased exposure years was analyzed. Results No significant difference existed between the two groups in age, gender, work experience and body mass index (BMI). The electromagnetic frequency band in the operation area was between 5.5-2000 MHz, the maximum power density could reach up to 14 W/m2in the shielding point, and reach up to 535.17 W/m2in the open area. Compared with the non-exposed group, the levels of mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and mean platelet volume (MPV) were significantly elevated (P<0.05), while the red blood cell count (RBC) and haematocrit (HCT) was markedly reduced (P<0.05) in the exposed group. With the prolongation of the exposure time, the levels of RBC and HCT were relatively stable, but MCH, MCHC and MPV showed fluctuation from higher to lower level. Conclusions Long-term exposure to strong electromagnetic environment may lead to lower levels of red blood cells in related workers. Compensation may be achieved through hemoglobin elevation at early stage, which nevertheless weakens through hemoglobin reduction during the exposure time prolonged.

E-noise: An increasingly relevant health risk / 中西医结合学报

This article briefly reviews and discusses the current status of major non-communicable diseases (mNCDs), definition of e-noise, its possible link as a risk factor for cardiovascular diseases and other mNCDs, and proposes possible mechanisms and hypotheses on that link, and how to control e-noise in the future. E-noise is defined as signal from electronic products and instruments that emit radiation and electromagnetic fields. It includes not only the acoustic but also non-acoustic noise. Just like road traffic and aircraft noises, e-noise may not only lead to hearing loss and health problems such as fatigue, stress, irritability, headache, and insomnia, but may also endanger cardiovascular health and result in hypertension, ischemic heart disease (myocardial infarction), arrhythmia (atrial fibrillation) and stroke; brain and metabolic problems such as obesity and diabetes; mental and cognitive impairment; as well as changing of humans' long-evolved cortisol and circadian rhythms after long-term exposure. Even short-term exposure to excessive e-noise may lead to heightened stress responses and low quality of life. In conclusion, e-noise is a potential danger in our world, and further studies are needed of its effects on mechanisms of aging, disease, and human health.

Long term power frequency electromagnetic fields exposure influences the causal network connection pattern of local field potentials during working memory / 生物医学工程学杂志

The possible influence of electromagnetic field (EMF) on the function of neural systems has been widely concerned. In this article, we intend to investigate the effects of long term power frequency EMF exposure on brain cognitive functions and it's mechanism. The Sprague-Dawley (SD) rats were randomly divided into 3 groups: the rats in EMF Ⅰ group were placed in the 2 mT power frequency EMF for 24 days. The rats in EMF Ⅱ group were placed in the 2 mT power frequency EMF for 48 days. The rats in control group were not exposed to the EMF. Then, the 16 channel local field potentials (LFPs) were recorded from rats' prefrontal cortex (PFC) in each group during the working memory (WM) tasks. The causal networks of LFPs were also established by applying the directed transfer function (DTF). Based on that, the differences of behavior and the LFPs network connection patterns between different groups were compared in order to investigate the influence of long term power frequency EMF exposure on working memory. The results showed the rats in the EMF Ⅱ group needed more training to reach the task correction criterion (over 80%). Moreover, the causal network connection strength and the global efficiency of the rats in EMF Ⅰ and EMF Ⅱ groups were significantly lower than the corresponding values of the control group. Meanwhile, significant differences of causal density values were found between EMF Ⅱ group and the other two groups. These results indicate that long term exposure to 2 mT power frequency EMF will reduce the connection strength and the information transfer efficiency of the LFPs causal network in the PFC, as well as the behavior performance of the rats. These results may explain the effect of EMF exposure on working memory from the view of neural network connectivity and provide a support for further studies on the mechanism of the effect of EMF on cognition.

Research progress in benchmark dose in risk assessment of long-team exposure toxicity / 军事医学

The purpose of risk assessment is to evaluate the permissible exposure level under specific risk factors.To extrapolate the human acceptable daily intake (ADI) and/or reference dose (RfD), the traditional method uses the no-observed-adverse-effect level ( NOAEL ) to quantify toxicity after being divided by uncertainty factor.There are many limitations with NOAEL method in safety evaluation,for it relies too much on experimental design.Benchmark dose ( BMD) approach is a more reliable method with many advantages.BMD approach and its analysis software, the advantages of BMD over NOAEL, the application and methodological perfection in risk assessment of long-team exposure toxicity are presented in this review.

Ordinary kriging approach to predicting long-term particulate matter concentrations in seven major Korean cities

OBJECTIVES: Cohort studies of associations between air pollution and health have used exposure prediction approaches to estimate individual-level concentrations. A common prediction method used in Korean cohort studies is ordinary kriging. In this study, performance of ordinary kriging models for long-term particulate matter less than or equal to 10 mum in diameter (PM10) concentrations in seven major Korean cities was investigated with a focus on spatial prediction ability. METHODS: We obtained hourly PM10 data for 2010 at 226 urban-ambient monitoring sites in South Korea and computed annual average PM10 concentrations at each site. Given the annual averages, we developed ordinary kriging prediction models for each of the seven major cities and for the entire country by using an exponential covariance reference model and a maximum likelihood estimation method. For model evaluation, cross-validation was performed and mean square error and R-squared (R2) statistics were computed. RESULTS: Mean annual average PM10 concentrations in the seven major cities ranged between 45.5 and 66.0 mug/m3 (standard deviation=2.40 and 9.51 mug/m3, respectively). Cross-validated R2 values in Seoul and Busan were 0.31 and 0.23, respectively, whereas the other five cities had R2 values of zero. The national model produced a higher crossvalidated R2 (0.36) than those for the city-specific models. CONCLUSIONS: In general, the ordinary kriging models performed poorly for the seven major cities and the entire country of South Korea, but the model performance was better in the national model. To improve model performance, future studies should examine different prediction approaches that incorporate PM10 source characteristics.