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To compare the effects of short-term exposure to particulate matter (PM) with different particle sizes on first-ever stroke risk in the middle-aged and elderly Chinese population. Health information was collected from the China National Stroke Screening Survey (CNSSS) from March 1, 2013, to April 10, 2015. Ambient exposures to PM 1 , PM 2.5 , and PM 10 were obtained from ChinaHighAirPollutants (CHAP) Grid data. Case-crossover design was used to estimate the increase of first-ever stroke risk per 10 μg/m3 increase in ambient exposures to different size particles. We used distributed lag linear model (DLM) to estimate the hysteresis effects of particle exposures. In addition, in order to assess the effect modification of long-term exposure, we did a stratified analysis using median exposure as the dividing line. We included 1326 first-ever stroke events from 242 communities in the present study. We found that effects on first-ever stroke risk increased with the decrease in particle size. The percent increases of first-ever stroke risk increased by 6.6% (95% CI: 1.4, 12.0), 3.3% (95% CI: 0.5, 6.1), and 0.6% (95% CI: -1.2, 2.6) per 10 g/m3 increases in PM 1 , PM 2.5 , and PM 10 exposures in lag 0–2 days, respectively. Furthermore, the cumulative effect of PM on first-ever stroke reached its peak at distinct time points under different layers of long-term PM exposure. In areas with low PM exposure, the cumulative effects of the three kinds of particles on stroke reached their peak in lag1 day, while the cumulative effect peaked in lag3 day in areas with high PM exposure. This study found that smaller particles had a stronger short-term effect on first-ever stroke. We also found that people in areas with long-term exposures to lower levels were more sensitive to short-term exposures. These results have public health significance for stroke prevention and air pollution reduction. [Display omitted] • The effects of PM on first-ever stroke in a large area were evaluated. • The impacts of PM increase with decreasing particle size. • The short-term effects of PM were larger in areas with lower long-term exposure levels. [ABSTRACT FROM AUTHOR]

The population history of Southeast (SE) China remains poorly understood due to the sparse sampling of present‐day populations and limited modeling with ancient genomic data. We report genome‐wide genotyping data from 207 present‐day Han Chinese and Hmong‐Mien (HM)‐speaking She people from Fujian and Taiwan Island, SE China. We coanalyzed 66 Early Neolithic to Iron Age ancient Fujian and Taiwan Island individuals obtained from previously published works to explore the genetic continuity and admixture based on patterns of genetic variations of the high‐resolution time transect. We found the genetic differentiation between northern and southern East Asians was defined by a north–south East Asian genetic cline and our studied southern East Asians were clustered in the southern end of this cline. The southeastern coastal modern East Asians are genetically similar to other southern indigenous groups as well as geographically close to Neolithic‐to‐Iron Age populations, but they also shared excess alleles with post‐Neolithic Yellow River ancients, which suggested a southward gene flow on the modern southern coastal gene pool. In addition, we identified one new HM genetic cline in East Asia with the coastal Fujian HM‐speaking She localizing at the intersection between HM and Han clines. She people show stronger genetic affinity with southern East Asian indigenous populations, with the main ancestry deriving from groups related to southeastern ancient indigenous rice farmers. The southeastern Han Chinese could be modeled with the primary ancestry deriving from the group related to the Yellow River Basin millet farmers and the remaining from groups related to rice farmers, which was consistent with the northern China origin of modern southeastern Han Chinese and in line with the historically and archaeologically attested southward migrations of Han people and their ancestors. Our estimated north–south admixture time ranges based on the decay of the linkage disequilibrium spanned from the Bronze Age to historic periods, suggesting the recent large‐scale population migrations and subsequent admixture participated in the formation of modern Han in SE Asia. [ABSTRACT FROM AUTHOR]

The Han Chinese are the world's largest ethnic group residing across China. Shaanxi province in northern China was a pastoral–agricultural interlacing region sensitive to climate change since Neolithic times, which makes it a vital place for studying population dynamics. However, genetic studies of Shaanxi Han are underrepresented due to the lack of high‐density sampling and genome‐wide data. Here, we genotyped 700 000 single nucleotide polymorphisms (SNPs) in 200 Han individuals from nine populations in Shaanxi and compared with available modern and ancient Eurasian individuals. We revealed a north–south genetic cline in Han Chinese with Shaanxi Han locating at the northern side of the cline. We detected the western Eurasian‐related admixture in Shaanxi populations, especially in Guanzhong and Shanbei Han Chinese in proportions of 2%–4.6%. Shaanxi Han were suggested to derive a large part of ancestry (39%–69%) from a lineage that also contributed largely to ancient and present‐day Tibetans (85%) as well as southern Han, supporting the common northern China origin of modern Sino‐Tibetan‐speaking populations and southwestward expansion of millet farmers from the middle‐upper Yellow River Basin to the Tibetan Plateau and to southern China. The rest of the ancestry of Shaanxi Han was from a lineage closely related to ancient and present‐day Austronesian and Tai‐Kadai speaking populations in southern China and Southeast Asia. We also observed a genetic substructure in Shaanxi Han in terms of north–south‐related ancestry corresponding well to the latitudes. Maternal mitochondrial DNA and paternal Y‐chromosome lineages further demonstrated the aforementioned admixture pattern of Han Chinese in Shaanxi province. [ABSTRACT FROM AUTHOR]

Ambient ozone (O 3) pollution has been associated with an increased risk of cardiovascular diseases. However, few studies have addressed the effect of O 3 exposure on electrocardiogram (ECG) abnormalities, a subclinical indicator of early damage to the cardiovascular system. This study aimed to examine the association between short-term exposure to O 3 and ECG abnormalities. We included 102,027 visits of 47,290 participants over 40 years old who had a normal ECG at baseline and then visited again at least once from the China National Stroke Screening Survey (CNSSS). Short-term ozone exposure concentrations were measured as averages of maximum daily 8-h O 3 concentrations over the two weeks prior to ECG measurements. The generalized estimation equations models were used to evaluate the association between O 3 exposure and ECG abnormalities. For every 10 µg/m3 increment in short-term O 3 concentration, the odds ratio of any ECG abnormality was 1.055 (95% confidence interval [CI] 1.045–1.064). For ECG-diagnosed cardiac arrhythmia, the odds ratio was 1.062 (95% CI 1.052–1.072). A nonlinear analysis showed a sublinear relationship between O 3 exposure and risk for ECG abnormalities. The association between O 3 exposure and ECG abnormalities varied by subpopulation. Our study provided new epidemiological evidence on the association between short-term O 3 exposure and ECG abnormalities. There is an urgent need to control ambient O 3 pollution to prevent cardiovascular events. [Display omitted] • Electrocardiogram abnormality as a subclinical indicator can reflect the early injury of cardiovascular system. • Short-term exposure to ozone is positively associated with ECG abnormalities in a large Chinese population. • Cardiovascular diseases should be prevented by reducing the occurrence of ECG abnormalities. [ABSTRACT FROM AUTHOR]