Exposure to multiple trace elements and thyroid cancer risk in Chinese adults: A case-control study.

The incidence of thyroid cancer (TC) has increased rapidly in last decades. Multiple trace elements in the external environment have important effects with thyroid function. However, the evidence for these on TC risk were rarely reported. A total of 585 newly diagnosed TC patients and 585 healthy controls were included in this study, and 14 urinary elements were measured to explain the fixed-exposure effect on TC risk. Conditional logistic regressions were used to reflect the multi-element associations, and Bayesian kernel machine regression (BKMR) was applied to show the tendency of mixed effects. Furthermore, the interaction effects were examined by Generalized linear model (GLM). The levels of lithium (Li), cobalt (Co), strontium (Sr), zinc (Zn) and copper (Cu) had negative effects with TC risk, nevertheless lead (Pb), arsenic (As) and chromide (Cr) showed positive effects. The BKMR and GLM models reflected the effect fluctuations of different elements, and there was a slight interaction effects between Li and Cr, Co, Zn and Pb. Further study is required to confirm these results in the future.

Interaction of biomass fuels use and metals exposure on hypertension: A prospective cohort study in rural areas along the Yangtze River, China.

Humans maybe simultaneously exposed to multiple-metals and indoor air pollution in daily life. However, limited prospective studies have assessed the interaction between multiple metals exposure and biomass fuels use on hypertension in China. The prospective cohort study in rural areas along the Yangtze River included 2625 adults in 2014-2015, and they were followed up till 2019. Among 1248 rural residents who were without hypertension at baseline, 377 hypertension events (30.21%) were observed after 4.5 years of average follow-up time. First-morning urine samples of residents were collected at baseline, the association between urinary metals level and hypertension were assessed using quantile g-computation. Additionally, we also examined the effect of biomass fuels use, fuels switching, and cookstove ventilation on the association of metals exposure with hypertension. Quantile g-computation analyses showed a positive joint effect of 17 metals on hypertension, with the odds ratio (OR) of 1.68 (95% CI: 0.89, 3.14) when increasing all seventeen metals by one quartile, and cadmium, lithium, copper contributed the largest positive weights. Biomass fuels use can interact with cadmium exposure on hypertension with OR for interaction of 1.28 (95%CI: 1.00, 1.73), and increase the association between copper, manganese and zinc exposure and systolic blood pressure, lithium exposure and diastolic blood pressure at the follow-up visit. Moreover, switching from biomass fuels to clean fuels during follow up, cookstove ventilation can alleviate the risk of higher blood pressure from metals exposure. In rural areas along the Yangtze River, China, biomass fuels use for cooking can interact with multiple-metals exposure on hypertension. Residents who switched from biomass fuels to clean fuels and who used ventilation had a lower risk of hypertension. Further cohort studies are needed to clarify the mechanism of combined effects of metals exposure and biomass fuels use on the human health.

Six air pollutants and cause-specific mortality: a multi-area study in nine counties or districts of Anhui Province, China.

Air pollution and its negative effects on health of people have been a global concern. Many studies had found a strong association between air pollutants and risk of death, but few had focused on the effects of six pollutants and rural areas. Our study aimed to investigate the effects of six air pollutants (CO, NO2, O3, PM2.5, PM10, and SO2) on non-accidental and respiratory deaths in rural areas of Anhui Province by adjusting for confounding factors, and to further clarify which populations were susceptible to death associated with air pollution. In the first phase of the analysis, the generalized additive models were combined with the distributed lag non-linear models to evaluate the individual effects of air pollution on death in each area. In the second stage, random-effects models were used to aggregate the associations between air pollutants and mortality risk in nine areas. Overall, six pollutants had the strongest effects on the risk of death on the lag 07 days. The associations between PM2.5 and NO2 and daily non-accidental deaths were strongest, with maximum RR (lag 07): 1.63 (1.37-1.88) and 1.67 (1.37-1.96). The maximum pooled effects of association between six air pollutants and RD were PM2.5, with RR (lag 07): 1.89 (1.45-2.34). PM2.5 and PM10 had significant differences between the elderly and the non-elderly with respectively, RRR: 1.22 (1.04-1.41) and 1.26 (1.11-1.42). In general, we found that six air pollutants were the important risk factors for deaths (deaths from respiratory disease and non-accidental) in rural areas of Anhui Province. PM10 and PM2.5 had a considerable impact on the elderly.

Associations of exposure to multiple trace elements with the risk of goiter: A case-control study.

Goiter is one of common endocrine diseases, and its etiology has not been fully elucidated. The changes in trace elements' levels have an important impact on the thyroid. We designed a case-control study, which involved 383 goiter cases and 383 matched controls. We measured these elements in the urine of participants by inductively coupled plasma optical emission spectrometry (ICP-OES), graphite furnace atomic absorption spectrometry (GFAAS) and As3+-Ce4+ catalytic spectrophotometry. Least Absolute Shrinkage and Selection Operator (LASSO) regression was used to select the elements into multi-element models, conditional logistic regression models were applied to analyze the association between elements and goiter risk. Bayesian kernel machine regression (BKMR) model was used to depict elements' mixtures and evaluate their joint effects. Finally, 7 elements were included in the multi-element model. We found that the concentrations of lithium (Li), strontium (Sr) and barium (Ba) had a negative effect with goiter risk, and lead (Pb) and iodine (I) showed an extreme positive effect. Additionally, compared with the lowest levels, patients with highest quartiles of I and Pb were 6.49 and 1.94 times more likely to have goiter, respectively. On the contrary, in its second and third quartiles, arsenic (As) showed a negative effect (both OR<1). BKMR model showed a certain interaction among Pb, As, Sr and Li on goiter risk. Further large sample studies are needed to confirm these findings in the future.

Reproductive and menstrual factors for papillary thyroid cancer risk: A case-control study in Chinese women.

BACKGROUND: Thyroid cancer (TC) is threefold more common in women than men. Reproductive and menstrual factors may be related to the onset of papillary thyroid cancer (PTC). This study aims to determine the association of reproductive and menstrual factors with PTC in Chinese females. METHODS: A total of 335 histologically confirmed cases of PTC were recruited in this case-control study. The controls were matched for age with a deviation of ± 2 years, which conducted from September 2016 to February 2019. Logistic regression models were applied to identify the association of reproductive and menstrual factors with PTC. RESULTS: After adjustment by some variables, early menarche age (OR ≤ 13 years vs. > 13years = 2.40, 95 % CI 1.12-5.13) and shorter lifetime breastfeeding (OR <6 months vs. ≥ 6 months = 1.99, 95 % CI 1.11-3.55) significantly increased the risk of PTC, whereas younger age at first pregnancy had a protective effect against PTC (OR ≤ 24years vs. > 24 years = 0.66, 95 % CI 0.44-0.98). There was a positive correlation between premenopausal and PTC in the lower age group (OR premenopausal vs. Menopause by natural =2.34, 95 %CI 1.03-5.28). CONCLUSIONS: Early menarche age, abortion, shorter breastfeeding duration and premenopausal may be related to the occurrence of PTC. Early age at first pregnancy and larger number of full-time pregnancies were possible to decrease the risk of PTC.

Prenatal exposure to phthalates with preterm birth and gestational age: A systematic review and meta-analysis.

Phthalates are non-persistent chemicals used in products of daily necessities. The evidence on the relationship of prenatal phthalates exposure and preterm birth remain uncertain and dimed. We Searched Cochrane, EMBASE, PubMed and Qvid Medline and selected studies according to a priori defined inclusion criteria. A total of 20 relevant studies published before March 31, 2020, were included. The main methods to detect heterogeneity and publication bias of included studies were the Q-statistic and Begg's test. Overall summary estimates indicated positive association of prenatal exposure to di(2-ethylhexyl) phthalate [number of studies (n) = 11, odds ratio (OR) = 1.1; 95% confidence interval (CI): 0.89, 1.4], diethyl phthalate [n = 11, OR = 1.1; 95% CI: 0.92, 1.3], dibutyl phthalate [n = 10, OR = 1.1; 95% CI: 0.77, 1.4], butyl benzyl phthalate [n = 10, OR = 1.0; 95% CI: 0.91, 1.2], diisobutyl phthalate [n = 9, OR = 1.1; 95% CI: 0.92, 1.3], diisononyl phthalate [n = 4, OR = 1.1; 95% CI: 0.85, 1.3], and phthalates were negatively associated with gestational age except di(2-ethylhexyl) phthalate and diisononyl phthalate. Most of them were not statistically significant. Subgroup analysis indicated that the heterogeneity was mainly found in the studies conducted in China and matrix collected at first trimester of pregnancy. Substantial heterogeneity and inconsistency of research methods may lead to inconsistent results of maternal phthalates exposure with preterm birth. We recommend a multicenter cohort study with a consistent approach to unravel the complex associations of prenatal phthalates exposure with birth outcomes.

Exposure to 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol and risk of thyroid cancer: a case-control study in China.

Thyroid cancer (TC) has inflicted huge threats to the health of mankind. Chlorophenols (CPs) were persistent organic pollutant and can lead to adverse effects in human health, especially in thyroid. However, epidemiological studies have revealed a rare and inconsistent relationship between internal exposure to CPs and TC risk. The purpose of this study was to investigate the correlation between urinary CPs and TC risk in Chinese population. From June 2017 to September 2019, a total of 297 histologically confirmed TC cases were recruited. Age- and gender-matched controls were enrolled at the same time. Gas chromatography-mass spectrometry (GC-MS) was used to determine the levels of three CPs in urine. Conditional logistic regression models were adopted to assess the potential association. Restricted cubic spline function was used to explore the non-liner association. After adjusting for confounding factors, multivariate analysis showed that, compared with the first quartile, the fourth quartile concentrations of 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), and pentachlorophenol (PCP) were associated with TC risk (odds ratio (OR)2,4-DCP =2.28, 95% confidence interval (CI): 1.24-4.18; OR2,4,6-TCP =3.09, 95% CI: 1.66-5.77; ORPCP =3.30, 95% CI: 1.71-6.36, respectively), when CPs were included in the multivariate model and restricted cubic spline function as continuous variables, presenting significant dose-response relationships. Meanwhile, whether in the TC group with tumor diameter > 1 cm or metastatic TC, the changes of 2,4,6 TCP and PCP concentrations were positively correlated with the risk of TC. Our study suggests that higher concentrations of urinary CPs are associated with increased TC risks. Moreover, 2,4,6-TCP and PCP have certain effects on the invasiveness of thyroid cancer. Targeted public health policies should be formulated to reduce the CP pollution. These findings need further in-depth studies to confirm and relevant mechanism also needed to be clarified.

Exposure to multiple metals and the risk of hypertension in adults: A prospective cohort study in a local area on the Yangtze River, China.

BACKGROUND: Exposure to multiple metals is recognized as a common and real scenario in daily life. However, limited prospective studies have assessed associations between multiple metals exposure and hypertension. METHODS: In total, 2625 adults in a local area on the Yangtze River were investigated at baseline from 2014 to 2015 and followed up in 2019. We measured baseline urine levels of 22 metals and used multivariate logistic analysis and Bayesian kernel machine regression (BKMR) to explore associations between multiple metals exposure and the risk of hypertension. RESULTS: A total of 385 individuals (29.6%) were diagnosed with hypertension. Five metals (cadmium, copper, magnesium, molybdenum and zinc) were positively associated with hypertension in single-metal models. Cadmium and zinc remained significantly positive associations after adjusting for these five metals, with the odds ratio (OR) in the highest quartiles of 1.49 (95% CI: 1.01, 2.21; p-trend = 0.05) and 1.60 (95% CI: 1.08, 2.38; p-trend = 0.02), respectively. BKMR analysis showed a significant joint effect of multiple metals on hypertension when the concentrations of five metals were at or above their 55th percentile compared with their median values. A potential interaction between cadmium and zinc in increasing the risk of hypertension was observed with the ORint of 1.41 (95%CI: 1.05, 1.89). CONCLUSIONS: We identified the joint effect of multiple metals on hypertension and observed a significant interaction between cadmium and zinc. Further cohort studies are needed to clarify the health effects of multiple metals exposure in a larger population.

Plasma polybrominated diphenyl ethers, urinary heavy metals and the risk of thyroid cancer: A case-control study in China.

The incidence of thyroid cancer (TC) has increased rapidly worldwide in recent years. Exposure to endocrine disruptors can affect thyroid hormones and is probably carcinogenic to humans. The effects of polybrominated diphenyl ethers (PBDEs), some heavy metals (Cd, Pb, As and Hg) on risk of TC have been rarely reported. Hence, we aimed to examine the associations of TC risk with exposure to PBDEs and four heavy metals. This case-control study involved 308 TC cases and 308 age- and sex-matched controls. Plasma PBDEs concentrations were determined by gas chromatograph-mass spectrometry. Concentrations of heavy metals concentrations in urine specimens were detected by graphite furnace atomic absorption spectrometry or inductively coupled plasma optical emission spectrometry. Conditional logistic regression models were used to explore associations of PBDEs and 4 heavy metals exposures with TC risk. A joint-effect interaction term was inserted into the logistic regression models to assess the multiplicative interaction effects of PBDEs-heavy metals on TC risk. Some PBDE congeners (BDE-028, -047, -099, -183, -209) were positively correlated with TC risk. As and Hg were also associated with the increased TC risk. Compared with low exposure levels, participants with high exposure levels of As and Hg were 5.35 and 2.98 times more likely to have TC, respectively. Co-exposure to BDE-209 and Pb had a negative interaction effect on TC risk. Some PBDE congeners (e.g. BDE-028, -047, -209) and Hg had a significant positive interaction effect on the risk of TC. The joint exposure of BDE-183 and Hg showed a negative interaction effect on TC risk, but the corresponding OR value was still statistically significant. Exposure to PBDEs, As and Hg may be associated with TC development. Joint exposure to PBDEs and Pb or Hg has interaction effects on TC risk. Further prospective research with large sample is required to confirm these findings.

Effect of the Interaction Between Cadmium Exposure and CLOCK Gene Polymorphisms on Thyroid Cancer: a Case-Control Study in China.

The exposure to endocrine disruptors and the disruption of the circadian rhythms can both affect thyroid hormones, with results that are most likely carcinogenic in humans. The effects of cadmium (Cd) level and circadian-related single-nucleotide polymorphisms (SNPs) on thyroid cancer (TC) risk have rarely been reported. In this study, the associations of urine Cd, CLOCK gene polymorphisms, and TC risk were evaluated, in addition to the effect of the gene-environment interaction on TC risk. In this case-control study, 218 TC cases and 218 controls were enrolled. Cd in urinary samples was determined by atomic absorption spectrometry. Three SNPs (rs3805151, rs3805154, and rs78929565) were genotyped with an improved multiplex ligation detection reaction technique. The individuals with a high Cd level were 1.72-fold more likely to have TC (OR = 1.72, 95%CI 1.04-2.85), and a high Cd level was associated with higher tumor T stage and N stage (OR = 2.42, 95%CI 1.28-4.58; OR = 3.26, 95%CI 1.67-6.33, respectively). Individuals with TT genotype of rs78929565 had a 107 % increase in TC risk (OR = 2.07, 95%CI 1.00-4.29). Cases with CT genotype tended to have a higher AJCC stage (OR = 2.79, 95% CI 1.01-7.78). A significant interaction was detected between the rs78929565 variant and Cd exposure (p interaction = 0.04). The TT genotype carriers of rs78929565 with a high Cd level were more susceptible to thyroid cancer than the major homozygotes carriers who were exposed to a low cadmium level (OR = 2.66, 95%CI 1.07-6.59). These findings suggested that Cd exposure and the CLOCK variant genotypes were associated with TC risk and tumor severity. Individuals with minor allele of rs78929565 and higher Cd exposure had increased susceptibility to TC. Further studies are required to confirm these findings.

Effects of extreme meteorological factors on daily mumps cases in Hefei, China, during 2011-2016.

Mumps remains one of the worldwide major health problems over the past decade. Seasonal variations of mumps indicate that meteorological factors play an important role in the development of mumps, but few studies have investigated the relationship between extreme meteorological factors and the incidence of mumps. Daily mumps cases and meteorological factors in Hefei, China, from 2011 to 2016 were obtained. A generalized additive model combined with the distributed lag nonlinear model (DLNM) was used to quantify the risk of extreme meteorological factors on mumps incidence. Nonlinear relationships were observed among all meteorological factors and mumps incidence. We found that extremely low and high temperatures increased the risk of mumps. The relative risks (RRs) of the cumulative effects along 30 lag days were 2.02 (95%CI: 1.14-3.56) and 2.42 (95%CI: 1.37-4.24), respectively. Both short and long sunshine duration had negative correlation on mumps, with cumulative RRs of 0.64 (95%CI: 0.46-0.92) and 0.57 (95%CI: 0.44-0.74), respectively. In the subgroup analysis, males were found to be more sensitive to extreme weather, especially extreme temperatures and sunshine duration. This study suggests that extreme meteorological factors, especially extreme temperatures and sunshine duration, exert a significant impact on the incidence of mumps. When formulating and implementing effective strategies to the prevention and control of mumps, authorities should take the effect caused by extreme meteorological factors into consideration and pay more attention to susceptible populations, such as male children and teenagers.

Association of exposure to multiple metals with papillary thyroid cancer risk in China.

Papillary thyroid cancer (PTC) has inflicted huge threats to the health of mankind. Metal pollution could be a potential risk factor of PTC occurrence, but existing relevant epidemiological researches are limited. The current case-control study was designed to evaluate the relationships between exposure to multiple metals and the risk of PTC. A total of 262 histologically confirmed PTC cases were recruited. Age- and gender-matched controls were enrolled at the same time. Urine samples were used as biomarkers to reflect the levels of environmental exposure to 13 metals. Conditional logistic regression models were adopted to assess the potential association. Single-metal and multi-metal models were separately conducted to evaluate the impacts of single and co-exposure to 13 metals. The increased concentration of urinary Cd, Cu, Fe, and Pb quartiles was found significant correlated with PTC risk. We also found the decreased trends of urinary Se, Zn, and Mn quartiles with the ORs for PTC. These dose-response associations between Pb and PTC were observed in the single-metal model and remained significant in the multi-metal model (OR25-50th=1.39, OR50-75th=3.32, OR>75th=7.62, p for trend <0.001). Our study suggested that PTC was positively associated with urinary levels of Cd, Cu, Fe, Pb, and inversely associated with Se, Zn, and Mn. Targeted public health policies should be made to improve the environment and the recognition of potential risk factors. These findings need additional studies to confirm in other population.

Association of maternal arsenic exposure with birth size: A systematic review and meta-analysis.

OBJECTIVES: Chronic exposure to arsenic during pregnancy or early life continues to be a major global health problem worldwide, affecting hundreds of millions of people. However, its effects on birth size are uncertain. The aim of this study is to summarized the association between maternal arsenic exposure and birth size. METHODS: A comprehensive literature search was conducted on the maternal arsenic exposure and birth size (birth weight, birth length, head circumference and chest circumference) through databases (PubMed, Qvid Medline, Web of Science, Cochrane and EMBASE), the last search was in March 2019. Heterogeneity was testes by using the Q statistic and stratifying for epidemiological factors. The possibility of publication bias was assessed through Begg's test. RESULTS: A total of 12 studies provided sufficient data were included. Meta-analysis revealed that maternal arsenic exposure was associated with the decrease of birth weight (ß = -25.0 g; 95% CI: -41.0, -9.0) and head circumference (ß = -0.12 cm; 95% CI: -0.24, -0.01) in random-effect model, birth length (ß = -0.12 cm; 95% CI: -0.17, -0.07) in fixed-effect model, no significant reduction was suggested in chest circumference (ß = -0.74 cm; 95% CI: -1.78, 0.3). In addition, we found that the birth weight decreased stronger in women living in the Americas, or appling the exposure marker of urine. CONCLUSIONS: Maternal arsenic exposure is associated with the decrease of the birth weight, length and head circumference. Millions of people are still exposured to high-level arsenic, therefore, high quality epidemiologic studies that involve large samples are necessary to determine the precise relationships between maternal arsenic exposure with birth size. And that effective mitigation measures are also need to prevent arsenic exposure in women of reproductive age.

[Estimation of dry matter accumulation in above-ground part of cotton by means of canopy reflectance spectra].

Through analyzing the relationships of the dry matter accumulation in above-ground part of cotton with the canopy reflectance of single waveband and all two-band combinations in ratio vegetation index (RVI, R(lamda1)/R(lamda2)), normalized difference vegetation index (NDVI, (R(lamda1)-R(lamda2))/(R(lamda1) + R(lamda2 and differential vegetation index (DVI, R(lamda1)-R(lamda2)), the characteristic spectral wavebands for indicating the dry matter accumulation in above-ground part of cotton were determined, and the corresponding prediction model was established. The results showed that the vegetation indices comprised of visible light (560 and 710 nm) and near infrared light (810, 870, 950, 1100 and 1220 nm) were highly related to the dry matter accumulation in the above-ground part of cotton, and the RVI (1100, 560) was the best spectral index for the estimation. The corresponding prediction model established by stepwise regression method was Y (g x m(-2)) = 66.274 x RVI (1100, 560)-148.84. It could be feasible to estimate the dry matter accumulation in above-ground part of cotton with remote sensing.

[Estimation of nitrogen concentration in cotton leaf based on canopy reflectance spectra].

Through analyzing the relationships of nitrogen concentration in cotton leaf under different nitrogen supply levels with canopy multi-spectral reflectance and its derived ratio vegetation index (RVI, rholambda1/rholambda2), normalized difference vegetation index (NDVI, (rho(lambda1) - rho(lambda2))/(rho(lambda1)) + rho(lambda2)) and differential vegetation index (DVI, rho(lambda1) - rho(lambda2)), the sensitive wave bands and prediction functions of cotton leaf nitrogen concentration were worked out. The vegetation index composed of visible region (610, 660, 680 and 710 nm) and near infrared region (760, 810, 870, 950, 1 100 and 1 220 nm) had a higher correlation with the nitrogen concentration in cotton leaf, and the RVI composed of 950 nm and 710 nm could best predict the leaf nitrogen concentration. The validation with independent field experimental data indicated that RVI (950 nm and 710 nm) -based model was suitable for estimation of leaf nitrogen concentration of different cotton cultivars at their different growth stages.