Association between air particulate matter pollution and blood cell counts of women preparing for pregnancy: Baseline analysis of a national birth cohort in China.

BACKGROUND: Limited evidence is known about whether long-term exposures to air borne particulate matters of 2.5 µm or less (PM2.5) impact human hematologic index for women preparing for pregnancy. No study assessed the effect of PM1, which is small enough to reach the blood circulation. OBJECTIVE: To evaluate whether exposure to PM1 and PM2.5 is associated with blood cell count of woman preparing for pregnancy. METHOD: Based on the baseline data of a national birth cohort in China, we analysed the white blood cell (WBC), red blood cells (RBC) and thrombocyte counts of 1,203,565 women who are aged 18-45 years, being Han ethnicity, had no chronic disease and preparing for pregnancy. We matched their home addresses and examination date with daily concentrations of PM1 and PM2.5 which were estimated by a machine learning method with remote sensing, meteorological and land use information. Generalized additive mixed model to examine the associations between exposure to one-year average exposure to PMs prior to the health examination and the blood cells counts, after adjustment for potential individual variables. RESULTS: A 10 µg/m3 PM1 increment was associated with -1.49% (95%CI: 1.56%, -1.42%) difference in WBC count; with 0.33% (95%CI: 0.30%, 0.36%) difference of RBC count; and with 1.08% (95%CI: 1.01%, 1.15%) difference of thrombocyte count. For PM2.5, the corresponding difference was -0.47% (95%CI: 0.54%, -0.39%) for WBC; was 0.06% (95%CI: 0.03%, 0.09%) for RBC; and was 1.10% (95%CI: 1.02%, 1.18%) for thrombocyte. Women working as workers, being overweight and with tobacco smoking exposure had higher associations between PMs and hematologic index than their counterparts (p < 0.05 for interaction test). CONCLUSION: Long-term exposure to PMs were associated with decrement in WBC, as well as increment in RBC and thrombocytes among Han Chinese women preparing for pregnancy. Measures such as using air purifiers and wearing a mask in polluted areas should be improved to prevent women from the impact of PMs.

Association between airborne particulate matter and renal function: An analysis of 2.5 million young adults.

BACKGROUND: Limited studies have examined the impact of airborne particulate matter of 2.5 µm or less (PM2.5) on renal function. No study has examined the effect of PM1, which is small enough to reach the blood circulation. We examined whether exposure to PM1 or PM2.5 affected renal function of young Han Chinese. METHOD: We included 2,546,047 young adults who were aged 18 to 45 years, being Han ethnicity and had no chronic disease from a Chinese national birth cohort. Serum creatinine (Scr) of each participant was measured during the baseline examination. Estimated glomerular filtration rate (eGFR) were calculated for each participant using the latest Chronic Kidney Disease Epidemiology Collaboration equation. One-year average exposure to PM1 and PM2.5 prior to the health examination for each participant were estimated using machine learning models with satellite remote sensing information. Generalized additive mixed models were used to estimate associations between PM1 or PM2.5 and renal function after adjusting for detailed individual variables. RESULTS: A 10 µg/m3 increment in PM1 exposure was associated with -0.95% (95%CI: -1.04%, -0.87%) difference of eGFR in females and -0.37% (95%CI: -0.44%, -0.31%) in males. For PM2.5, the corresponding difference of eGFR was -0.99% (95%CI: -1.05%, -0.93%) in females and -0.48% (95%CI: -0.53%, -0.43%) in males, respectively. Associations between eGFR and PM were higher in females compared to males (p < 0.05 for interaction test). Association with PM1 were weaker than that with other fractions included in PM2.5. Participants who worked as farmers, were of normal weight, were not exposed to tobacco smoking, did not drink alcohol, had higher associations between eGFR and PM than their counterparts (p < 0.05 for interaction test). CONCLUSION: Exposure to PM1 and PM2.5 was associated with reduced renal function among Han Chinese at reproductive age.

Folic Acid Supplementation and the Association between Maternal Airborne Particulate Matter Exposure and Preterm Delivery: A National Birth Cohort Study in China.

BACKGROUND: Potential modification of the association between maternal particulate matter (PM) exposure and preterm delivery (PTD) by folic acid (FA) supplementation has not been studied. OBJECTIVE: We examined whether FA supplementation could reduce the risk of PTD associated with maternal exposure to PM in ambient air during pregnancy. METHOD: In a cohort study covering 30 of the 31 provinces of mainland China in 2014, 1,229,556 primiparas of Han ethnicity were followed until labor. We collected information on their FA supplementation and pregnancy outcomes and estimated each participant's exposure to PM with diameters of ≤10µm (PM10), 2.5µm (PM2.5), and 1µm (PM1) using satellite remote-sensing based models. Cox proportional hazard regression models were used to examine interactions between FA supplementation and PM exposures, after controlling for individual characteristics. RESULTS: Participants who initiated FA ≥3 months prior to pregnancy (38.1%) had a 23% [hazard ratio (HR)=0.77 (95% CI: 0.76, 0.78)] lower risk of PTD than women who did not use preconception FA. Participants with PM concentrations in the highest quartile had a higher risk of PTD [HR=1.29 (95% CI: 1.26, 1.32) for PM1, 1.52 (95% CI: 1.46, 1.58) for PM2.5, and 1.22 (95% CI: 1.17, 1.27) for PM10] than those with exposures in the lowest PM quartiles. Estimated associations with a 10-µg/m3 increase in PM1 and PM2.5 were significantly lower among women who initiated FA ≥3 months prior to pregnancy [HR=1.09 (95% CI: 1.08, 1.10) for both exposures] than among women who did not use preconception FA [HR=1.12 (95% CI: 1.11, 1.13) for both exposures; pinteraction<0.001]. The corresponding association was also significantly lower for a 10-µg/m3 increase in PM10 [HR=1.03 (95% CI: 1.02, 1.03) for FA ≥3 months before pregnancy vs. 1.04 (95% CI: 1.03, 1.04) for no preconception FA; pinteraction<0.001]. CONCLUSION: Our findings require confirmation in other populations, but they suggest that initiating FA supplementation ≥3 months prior to pregnancy may lessen the risk of PTD associated with PM exposure during pregnancy among primiparas of Han ethnicity. https://doi.org/10.1289/EHP6386.

Ambient temperature and the risk of preterm birth: A national birth cohort study in the mainland China.

BACKGROUND: Little is known about the effect of ambient temperature on preterm birth, especially for the trimester-specific effects. OBJECTIVE: To evaluate whether exposure to relatively low or high temperature during pregnancy is associated with increasing risk of preterm birth or not. METHOD: We analysed the data of a birth cohort with 1,281,859 singleton pregnancies during 2013-2014 and matched the home address of each pregnant women to the model based daily meteorological and air pollution data. Then we used the Cox proportional hazard regression models with random effect to estimate the non-linear associations between exposure to relatively low or high temperature at each trimester of pregnancy and the risk of preterm birth, after controlling for air pollution and individual-level covariates. FINDING: The overall preterm birth rate was 8.1% (104,493 preterm births). Exposure to relatively low or high temperatures during the entire pregnancy significantly increase the risk of preterm birth, with hazard ratios (HRs) [95% confidence intervals (CIs)] of 1.03 (95%CI: 1.02, 1.04) for relatively low (9.1 ℃, the 5th percentile) temperature and 1.55 (95%CI: 1.48, 1.61) for relatively high (23.0 ℃, the 95th percentile) temperature in comparison with the thresholds (12.0 ℃). Pregnant women at the early pregnancy (the 1st and 2nd trimester) are more susceptible to high temperatures while pregnant women at the late pregnancy (the 3rd trimester) are more susceptible to low temperatures. CONCLUSION: These findings provide new evidence that exposure to relatively low or high temperatures during pregnancy increases the risk of preterm birth, which can serve as scientific evidence for prevention of preterm birth.

Long-term exposure to airborne particulate matter of 1 µm or less and blood pressure in healthy young adults: A national study with 1.2 million pregnancy planners.

No evidence exists concerning the effect of airborne particulate matter of 1 µm or less (PM1) on blood pressure of young adults planning for pregnancy. We collected health examination information of about 1.2 million couples (aged 18-45 years) from a national birth cohort in China from Jan 1, 2013 to Oct 1, 2014 and matched their home address to daily PM1 and PM2.5 concentrations, which were predicted by remote sensing information. Generalized additive mixed models were used to analyze associations between long-term exposure to PM and blood pressure, after controlling for individual factors. A 10 µg/m3 increase in PM1 was associated with increased systolic blood pressure (SBP) for 0.26 (95%CI: 0.24, 0.29) mmHg in females and 0.29 (95%CI: 0.26, 0.31) mmHg in males, respectively. PM1 was also associated with increased DBP for 0.22 (95%CI: 0.20, 0.23) mmHg in females and 0.17 (95%CI: 0.15, 0.19) mmHg in males, respectively. Similar effects on blood pressure were found for PM2.5, meanwhile, the effect of PM2.5 on SBP increased with the scale of PM1 included in PM2.5 (p for interaction term <0.01). In summary, long-term exposure to PM1 as well as PM2.5 was associated with increased SBP and DBP of Chinese young adults planning for pregnancy.

Status of HBsAg seroprevalence in 15 million rural couples in China: a cross-sectional study.

A cross-sectional analysis of prevalence of hepatitis B virus infection (HBV) among rural couples was conducted between 2010 and 2014. Serologic HBV markers, including hepatitis B surface antigen (HBsAg) and e antigen (HBeAg), were tested. Primary outcome of interest comprised HBsAg positivity in couples (both positive: F+M+, only wife positive: F+M-, only husband positive: F-M+), and secondary outcome consisted of prevalence and risk factors of HBsAg positivity among husbands or wives. Of 14,816,300 couples included, 0.7% were F+M+; 6.3% were F-M+; 4.4% were F+M-, resulting in the overall seroprevalence of 11.4%. Individually, 6.1% were HBsAg positive with a higher rate seen in husbands (7.0%) than in wives (5.2%). Wife's HBeAg(+)/HBsAg (+) (AOR = 2.61), HBeAg(-)/HBsAg (+) (AOR = 2.23), positivity of syphilis (AOR = 1.50), living in a high-risk region (AOR = 1.46) were significantly predictors of HBsAg positivity in husbands. Prevalence and predictors of HBsAg positivity in wives had similar results. Our data show a high burden and discordant pattern of HBV infection in rural couples, and partner's double positivity of HBeAg and HBsAg was the most significant factor of HBV infection in couples. A comprehensive strategy that emphasizes vaccination and education is needed.

Spatial patterns of the congenital heart disease prevalence among 0- to 14-year-old children in Sichuan Basin, P. R China, from 2004 to 2009.

BACKGROUND: Congenital heart disease (CHD) is the most common type of major birth defects in Sichuan, the most populous province in China. The detailed etiology of CHD is unknown but some environmental factors are suspected as the cause of this disease. However, the geographical variations in CHD prevalence would be highly valuable in providing a clue on the role of the environment in CHD etiology. Here, we investigate the spatial patterns and geographic differences in CHD prevalence among 0- to 14-year-old children, discuss the possible environmental risk factors that might be associated with CHD prevalence in Sichuan Basin from 2004 to 2009. METHODS: The hierarchical Bayesian model was used to estimate CHD prevalence at the township level. Spatial autocorrelation statistics were performed, and a hot-spot analysis with different distance thresholds was used to identify the spatial pattern of CHD prevalence. Distribution and clustering maps were drawn using geographic information system tools. RESULTS: CHD prevalence was significantly clustered in Sichuan Basin in different spatial scale. Typical hot/cold clusters were identified, and possible CHD causes were discussed. The association between selected hypothetical environmental factors of maternal exposure and CHD prevalence was evaluated. CONCLUSIONS: The largest hot-spot clustering phenomena and the CHD prevalence clustering trend among 0- to 14-year-old children in the study area showed a plausibly close similarity with those observed in the Tuojiang River Basin. The high ecological risk of heavy metal(Cd, As, and Pb)sediments in the middle and lower streams of the Tuojiang River watershed and ammonia-nitrogen pollution may have contribution to the high prevalence of CHD in this area.

[Standardization for sharing and utilization of Chinese genetic resources].

National Infrastructure of Chinese Genetic Resources is a part of National Infrastructure of Natural Resources for Science and Technology. To strengthen and standardize the collection, integration, conservation, sharing and utilization of Chinese Genetic Resources, we have been carrying out the research on standardization of trimming, integration and sharing of Chinese Genetic Resources, according the advanced experiences abroad on that and abiding by the related laws and regulations. In the paper, National Infrastructure of Chinese Genetic Resources will be introduced on the standardization of integration, database construction and sharing of Chinese Genetic Resources.

Chinese weight-correction model for maternal serum markers in Down syndrome prenatal screening.

OBJECTIVE: To determine the best weight-correction model by means of analyzing the relationship between maternal weight and maternal serum markers when screening for Down syndrome in China. METHODS: Serum levels of alpha-fetoprotein (AFP) and free beta-human chorionic gonadotropin (hCG) were measured in 35,917 Chinese women during the second semester of a normal singleton pregnancy and converted to multiple of median (MoM) values. Using 2 methods of statistical analysis, the all-point method and the median regression method, 4 weight-correction models were then tried, the simple linear, reciprocal, quadratic, and log-linear regression models. RESULTS: The median regression method performed better than the all-point method, and the quadratic regression model showed the best fit for both AFP and hCG in the median regression method, with adjusted R(2)s of 0.987 and 0.988, respectively. CONCLUSION: The quadratic regression model was found to be the most suitable for Chinese pregnant women.

[CAG repeats of DNA polymerase gamma in Chinese males and relationship of idiopathic male infertility to CAG repeats].

OBJECTIVE: To analyze the polymerase gamma(Polg) gene polymorphisms in Chinese idiopathic infertile males and evaluate the correlation of the polymorphisms with male infertility. METHODS: We conducted a study of Polg CAG repeats in the sperm or blood DNA of 55 asthenospermia patients, 57 oligospermia patients, 34 azoospermia patients, and 104 controls with PCR and GeneScan. Phenotypic data were available in all the subjects, including semen parameters, and clinical profiles. RESULTS: The frequency of 10/not 10 CAG genotype in asthenospermia patients was higher than in the other groups, but with no significance. CONCLUSION: Our findings have shown for the first time that there exits an ethnic difference between Chinese and European males in the number of CAG repeats of Polg gene, and that 10/not 10 CAG genotype may affect sperm motility.