Association between polycyclic aromatic hydrocarbon exposure and liver function: The mediating roles of inflammation and oxidative stress.

Polycyclic aromatic hydrocarbon (PAH) exposure has been associated with adverse health effects, and accumulating evidence suggests that PAH exposure may impair liver function. However, the underlying mechanisms linking PAH exposure and liver function impairment remain unclear. This study aimed to explore the association between PAH exposure and liver function biomarkers, and the mediating effects of inflammation and oxidative stress. The cross-sectional study included 155 adults and their urinary PAH metabolites (OH-PAHs) were determined, and eight liver function biomarkers were measured in paired serum samples. A comprehensive statistical analysis investigated the linear, non-linear, individual, and joint effects of the association between urinary OH-PAHs and liver function biomarkers. The results indicated significant positive associations between urinary OH-PAH concentrations and liver function biomarker levels, suggesting that PAH exposure may adversely affect liver function. 2-hydroxyfluorene was identified as the individual metabolite contributing significantly to elevated gamma-glutamyl transferase levels. Further stratification by gender revealed that this association is more pronounced in males. Moreover, we observed significant mediation effects of the oxidative stress biomarker 8-hydroxy-2'-deoxyguanosine and the inflammatory biomarkers C-reactive protein and white blood cell count on this association. The physiological responses triggered by PAH exposure are mediated by inflammation, which serves as a link between oxidative stress, cellular injury, and elevated liver enzyme levels. The results demonstrated that increased inflammation and oxidative stress mediated the association between increased urinary OH-PAHs and elevated liver function biomarkers. The results contribute to a better understanding of the potential mechanisms underlying PAH exposure's hepatotoxic effects.

Association of co-exposure to polycyclic aromatic hydrocarbons and phthalates with oxidative stress and inflammation.

Exposure to multiple environmental pollutants is ubiquitous and inevitable, but studies investigating their exposure effects on oxidative stress or inflammation have mainly been restricted to single-pollutant models. This study investigated the association of co-exposure to polycyclic aromatic hydrocarbons and phthalates with oxidative stress and inflammation. Using a cross-sectional study in adults, we measured urinary concentrations of metabolites of polycyclic aromatic hydrocarbons (OH-PAHs) and phthalates (mPAEs), urinary oxidative stress biomarker 8-hydroxy-2'-deoxyguanosine, and 9 inflammatory biomarkers in paired blood samples. The associations of urinary OH-PAHs and mPAEs with oxidative stress and inflammation biomarkers were evaluated by different statistical models. The Bayesian kernel machine regression and quantile g-computation was used to examine the joint effects, and increased levels of urinary concentrations of OH-PAHs and mPAEs were associated with elevated 8-hydroxy-2'-deoxyguanosine level and white blood cell counts. Exposure to polycyclic aromatic hydrocarbons contributed more significantly to inflammation, while exposure to phthalates contributed more to oxidative stress. Monoisobutyl phthalate was identified as the most significant metabolite contributing to elevated oxidative stress levels. 1-Hydroxypyrene was negatively associated with platelet, and monomethyl phthalate was significantly positively associated with interleukin 6 in multivariate linear regression. The restricted cubic spline analysis revealed non-linear patterns of 3-hydroxyfluorene with white blood cell, lymphocyte, neutrophil, and C-reactive protein. The results indicated significant associations between increased co-exposure to polycyclic aromatic hydrocarbons and phthalates with elevated oxidative stress and inflammation. Further investigation is needed to elucidate the underlying biological mechanisms and to determine the potential public health implications.

Association between polycyclic aromatic hydrocarbon exposure and blood lipid levels: the indirect effects of inflammation and oxidative stress.

Although previous studies have indicated polycyclic aromatic hydrocarbons (PAHs) as cardiovascular health risk factors, evidence linking exposure to PAHs and blood lipids is still lacking, and the mechanism remains largely unknown. In this study, we evaluated the association between human internal exposure to PAHs and blood lipid levels in adults, as well as the indirect effects of inflammation and oxidative stress. The internal exposure of PAHs was assessed by determining serum PAHs and their hydroxylated metabolites (OH-PAHs) in the paired urine samples. Multivariable linear regression results demonstrated significant positive associations of individual PAHs and OH-PAHs with blood lipid biomarkers. The Bayesian kernel machine regression model revealed positive joint effects of PAH internal exposure on the fasting blood glucose, low-density lipoprotein cholesterol, total cholesterol, and total triglyceride, as well as an increased ratio of apolipoprotein B to apolipoprotein A1. In evaluating individual effects, serum phenanthrene played the most significant role in the association of increased PAH exposure with elevated fasting blood glucose. Quantile g-computation demonstrated the significant change in the levels of apolipoprotein B, ratio of apolipoprotein B to apolipoprotein A1, low-density lipoprotein cholesterol, and total cholesterol per quartile increase in PAH internal exposure. The restricted cubic spline analysis demonstrated the non-linear relationship between individual PAHs and OH-PAHs on blood lipid biomarkers. The mediation analysis indicated that PAH exposure may affect blood lipids not directly, but rather indirectly through intermediate inflammation and oxidative stress. The results demonstrated a significant association between increased PAH exposure levels and elevated blood lipids, highlighting the indirect effects of inflammation and oxidative stress.

Unraveling the contribution of dietary intake to human phthalate internal exposure.

Human exposure to phthalates (PAEs) occurs primarily through diet, but the contribution of dietary exposure to the total internal exposure of PAEs has not been well studied. This work investigated the relationship between dietary exposure and human internal exposure to PAEs. Daily food samples were determined to evaluate the health risk of dietary exposure, and phthalate metabolites (mPAEs) were determined from urine samples of 360 volunteers of Guangzhou to assess their internal exposure. The total mPAEs concentration in the urine samples ranged from 8.43 to 1872 ng/mL, with mono-(2-ethylhexyl) phthalate (MEHP), mono-n-butyl phthalate (MnBP), and mono-isobutyl phthalate (MiBP) being the most predominant mPAEs. The concentration of PAEs in food ranged from n.d-40200 µg/kg, and benzyl butyl phthalate (BBzP), di-n-butyl phthalate (DnBP) and di-(2-ethylhexyl) phthalate (DEHP) were the most prevalent. PAE exposure was significantly associated with age, and children exhibited the highest concentration of mPAEs. Using Monte Carlo simulation to estimate PAE exposure's health risk eliminated uncertainties caused by single-point sampling and provided more reliable statistical results. The hazard quotient (HQ) was used to evaluate PAE exposure health risks. The results showed that 37% of the volunteers had HQ levels higher than 1 based on urinary mPAE concentrations, while 24% of the volunteers had HQ levels greater than 1 because of dietary exposure to PAEs. Dietary intake was the predominant exposure route for PAEs, and accounted for approximately 65% (24% out of 37%) of the cases where HQ levels exceeded 1. The work revealed the correlation between dietary external and internal exposure to PAEs, and further studies are needed to better understand the implications.

Association of polycyclic aromatic hydrocarbon internal exposure and urinary iodine concentration with thyroid volume in children.

Thyroid volume was proposed as a factor for malignancy in evaluating thyroid nodules. Previous studies have demonstrated the endocrine disrupting effect of polycyclic aromatic hydrocarbons (PAHs), but studies on the association between internal exposure of PAHs and thyroid volume are still scarce. In this work, we evaluated the association of polycyclic aromatic hydrocarbon internal exposure and urinary iodine concentration with thyroid volume in 590 school-age children without thyroid disease in Guangzhou, China. Urinary hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs), urinary iodine concentrations, and thyroid volumes were measured. The mean concentrations of urinary iodine and ΣOH-PAHs were 271.1 µg/L and 3.27 µg/L, respectively, and the mean thyroid volume was 2.4 mL. The associations of urinary iodine and OH-PAH concentrations with thyroid volume were investigated by multivariable linear regression and the Bayesian kernel machine regression models. Urinary ΣOH-PAHs were observed to be significantly positively associated with thyroid volume in multivariable linear regression models. The increase in each unit in the log-transformed concentration of ΣOH-PAHs caused 3.88% change in thyroid volume. The Bayesian kernel machine regression model demonstrated a positive joint effect of increased urinary ΣOH-PAHs on thyroid volume. Moreover, urinary ΣOH-PAHs were statistically significant linked to urinary iodine, and iodine mediated the relationship between urinary OH-PAHs and thyroid volume with the mediated proportions of 15.2.

Supported liquid extraction and ultra-high performance liquid chromatography-tandem mass spectrometry for the determination of urinary polycyclic aromatic hydrocarbon metabolites and their application for human biomonitoring.

Polycyclic aromatic hydrocarbons (PAHs) are a class of highly lipophilic and ubiquitous, persistent organic pollutants with carcinogenic and mutagenic toxicities. They are a great public health concern, and avoiding exposure to them is a high priority. Human biomonitoring is critical for the evaluation of exposure levels to PAHs by the general population. In this work, we demonstrated the biomonitoring of eleven hydroxylated PAHs (OHPAHs) in urine samples from 226 volunteers from Guangzhou, and evaluated the health risks. The urinary PAH metabolites were released by enzymatic deconjugation, separated, and enriched by supported liquid extraction, and then quantified by ultra-high performance liquid chromatography-tandem mass spectrometry. The limit of quantification of the individual OHPAHs ranged from 10 ng/L to 40 ng/L, and satisfactory recoveries were obtained, ranging from 92.6% to 97.6%. The detection frequencies of the OHPAHs were 100%, and naphthalene metabolites were found at the highest concentrations with a geometric mean of 8.61 µg/L. The mean total OHPAH level in the urine samples of males (13.2 µg/L) was significantly higher than that of females (5.84 µg/L). Pearson correlation analyses indicated significant and positive correlations among urinary OHPAHs. The total estimated daily intake of PAHs was calculated, and a low health risk was obtained by evaluating their hazard quotients and hazard indexes.

Urinary heavy metals in residents from a typical city in South China: human exposure and health risks.

Although heavy metal pollution has developed into a major global environmental problem, most research has focused on specific elements, especially arsenic (As) and selenium (Se), and on the health risks to people in polluted areas or by occupation. This study investigated the urine of 480 participants from Guangzhou with a population of 18 million and targeted nine heavy metals: As, Se, chromium (Cr), manganese (Mn), nickel (Ni), cadmium (Cd), lead (Pb), antimony (Sb), and mercury (Hg). The heavy metals were widely detected, of which As, Se, Cd, and Pb all exceed 98%. Among the toxicants, As showed the highest concentration, followed by Se with 40.5 and 35.4 µg/L, respectively. The heavy metal levels from suburban subjects were generally higher than those in urban subjects (except for Sb), and the Cd level of males was lower than that of females. Concentrations were related to age, body mass index, alcohol consumption, and smoking. According to the health risk assessment, most subjects experienced potential non-carcinogenic risk from As, Cd, Se, and Hg, which accounted for 38.2%, 8.83%, 8.31%, and 3.38%, respectively. The carcinogenic risk of As and Cd surpassed the risk level of 10-6, and 90.1% and 35.4% of the subjects, respectively, exceeded 10-4, an unacceptable risk level. More attention to the high carcinogenic risk from heavy metals and the high detected levels of As and Cd is required.

Human health risks estimations from polycyclic aromatic hydrocarbons in serum and their hydroxylated metabolites in paired urine samples.

Polycyclic aromatic hydrocarbons (PAHs) are compounds with two or more benzene rings whose hydroxylated metabolites (OH-PAHs) are excreted in urine. Human PAH exposure is therefore commonly estimated based on urinary OH-PAH concentrations. However, no study has compared PAH exposure estimates based on urinary OH-PAHs to measurements of PAH levels in blood samples. Estimates of PAH exposure based solely on urinary OH-PAHs may thus be subject to substantial error. To test this hypothesis, paired measurements of parent PAHs in serum and OH-PAHs in urine samples from 480 participants in Guangzhou, a typical developed city in southern China, were used to investigate differences in the estimates of human PAH exposure obtained by sampling different biological matrices. The median PAH concentration in serum was 4.05 ng mL-1, which was lower than that of OH-PAHs in urine (8.33 ng mL-1). However, serum pyrene levels were significantly higher than urinary levels of its metabolite 1-hydroxypyrene. Concentrations of parent PAHs in serum were not significantly correlated with those of their metabolites in urine with the exception of phenanthrene, which exhibited a significant negative correlation. Over 28% of the participants had carcinogenic risk values above the acceptable cancer risk level of 10-6. Overall, estimated human exposure and health risks based on urinary 1-hydroxypyrene levels were only 13.6% of those based on serum pyrene measurements, indicating that estimates based solely on urine sampling may substantially understate health risks due to PAH exposure.

Community evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission through air.

BACKGROUND: Nine COVID-19 (Corona Virus Disease, 2019) cases were observed in one community in Guangzhou. All the cases lived in three vertically aligned units of one building sharing the same piping system, which provided one unique opportunity to examine the transmission mode of SARS-CoV-2. METHODS: We interviewed the cases on the history of travelling and close contact with the index patients. Respiratory samples from all the cases were collected for viral phylogenetic analyses. A simulation experiment in the building and a parallel control experiment in a similar building were then conducted to investigate the possibility of transmission through air. RESULTS: Index patients living in Apartment 15-b had a travelling history in Wuhan, and four cases who lived in Apartment 25-b and 27-b were subsequently diagnosed. Phylogenetic analyses showed that virus of all the patients were from the same strain of the virus. No close contacts between the index cases and other families indicated that the transmission might not occur through droplet and close contacts. Airflow detection and simulation experiment revealed that flushing the toilets could increase the speed of airflow in the pipes and transmitted the airflow from Apartment 15-b to 25-b and 27-b. Reduced exhaust flow rates in the infected building might have contributed to the outbreak. CONCLUSIONS: The outbreak of COVID-19 in this community could be largely explained by the transmission through air, and future efforts to prevent the infection should take the possibility of transmission through air into consideration. A disconnected drain pipe and exhaust pipe for toilet should be considered in the architectural design to help prevent possible virus spreading through the air.

Co-exposure and health risks of parabens, bisphenols, triclosan, phthalate metabolites and hydroxyl polycyclic aromatic hydrocarbons based on simultaneous detection in urine samples from guangzhou, south China.

Polycyclic aromatic hydrocarbons (PAHs) and certain ingredients in personal care products, such as parabens, bisphenols, triclosan and phthalate metabolites, have become ubiquitous in the world. Concerns of human exposure to these pollutants have increased during recent years because of various adverse health effects of these chemicals. Multiple compounds including parabens, bisphenols, triclosan, phthalate metabolites (mPAEs) and hydroxyl PAHs (OH-PAHs) in urine samples from Guangzhou were determined simultaneously to identify the human exposure pathways without external exposure data combined with data analysis, and the toxicants posed the highest risk to human health were screened in the present study. The detection frequencies for the chemicals exceeded 90%. Among the contaminants, mPAEs showed the highest concentrations, followed by OH-PAHs, with triclosan present at the lowest concentrations. Mono-n-butyl phthalate, methylparaben, bisphenol A, and hydroxynaphthalene represented the most abundant mPAE, parabens, bisphenol, and OH-PAH compounds, respectively. The present PAHs are mainly exposed to human through inhalation, while the chemicals added to personal care products are mainly exposed to human through oral intake and dermal contact. The urine samples from suburban subjects showed significantly higher OH-PAH levels than the urine samples from urban subjects, and females had lower OH-PAH levels than males. Urinary concentrations of the analyzed contaminants were significantly correlated with age, body mass index, residence time, as well as the frequencies of alcohol consumption and swimming. Risk assessments based on Monte Carlo simulation indicated that approximately 30% of the subjects suffered non-carcinogenic risks from mPAEs and OH-PAHs, with mPAEs accounting for 89% of the total risk.

The impact of discharge reduction activities on the occurrence of contaminants of emerging concern in surface water from the Pearl River.

"Swimming across the Pearl River" is an annual large-scale sporting event with great popularity in Guangzhou. To reduce the risk of swimmers' exposure to various contaminants in the Pearl River during swimming activities, the local government limits direct sewage and effluent discharge from urban channels during the event. However, the impact of discharge reduction on some contaminants of emerging concern (CECs), such as organophosphorus flame retardants (OPFRs), bisphenol analogues (BPs), and triclosan remains unknown. In the present study, the concentrations of CECs, as well as ammonia-nitrogen (NH3-N), dissolved organic carbon, and chemical oxygen demand, were measured in aqueous and suspended particulate matter (SPM) from the Guangzhou reaches of the Pearl River. The concentration ranges of sixteen OPFRs, eight BPs, and triclosan were 21.2-91.0, 8.46-37.3, and 1.47-5.62 ng/L, respectively, in aqueous samples, and 25.2-492, 14.0-86.3, and 0.69-17.5 ng/g, respectively, in SPM samples. Hydrophobic and π-π interactions could be contributing to the distribution of CECs. Principal component analysis indicated that consumer materials, manufacturing, and domestic sewage might be the main sources of the CECs. In addition, our study showed that the concentrations of CECs did not change considerably before or after discharge reduction activities, although NH3-N showed a substantial decrease following pollution control measure. The results demonstrated that temporary reductions of contaminant discharges to the Pearl River had only limited effect on the levels of CECs. Further research is needed to investigate the distributions and potential health risks of CECs in the Pearl River.

The anticaries effects of pit and fissure sealant in the first permanent molars of school-age children from Guangzhou: a population-based cohort study.

BACKGROUND: Analyses of the effects of pit and fissure sealant have been based on small samples and lack large-scale field evaluation data in China. The aim of this study was to understand the effect of pit and fissure sealant in preventing caries in the first permanent molars (FPMs) of children in Guangzhou. METHODS: We conducted a population-based cohort study using the database of the pit and fissure sealant program of Guangzhou. The carious status and sealant retention of the FPMs were assessed in 4,822 school children who received pit and fissure sealant 3 years prior to the study. The control group included 4,396 children who had indications for receiving pit and fissure sealant but were not treated and were matched according to sex, age and school. RESULTS: In the sealant group, the rate of sealant retention in the FPMs was 72.2%. Children in the sealant group had a 37% decreased risk of dental caries compared with the control group (adjusted HR = 0.63 [95% confidence interval (CI), 0.57-0.69], P < 0.001). Compared to no sealant use, the use of pit and fissure sealants reduced the risk of developing dental caries by 44% after 3 years in the FPMs of children from rural areas, reflecting a greater reduction than that among urban children (35%) during the same period (urban: adjusted hazard ratio (HR) = 0.65 [95% CI, 0.58-0.72]; rural: adjusted HR = 0.56 [95% CI, 0.45-0.70], P < 0.001). The mean number of decayed, missing, or filled permanent teeth (DMFT) in the control group was higher than that in the sealant group, and the difference was statistically significant regardless of sex. CONCLUSIONS: Pit and fissure sealant has a significant preventive effect against dental caries in the FPMs, especially for children in rural areas; thus, this sealant represents an effective technique for preventing and controlling dental caries.

Prevalence of body dissatisfaction and its effects on health-related quality of life among primary school students in Guangzhou, China.

BACKGROUND: The relationship between body dissatisfaction (BD) and health-related quality of life (HRQoL) has been well documented in adolescents and adults but is less clear in children, particularly in China. The aims of this study were to describe body image perception and dissatisfaction and to examine their effects on HRQoL among primary school students in Guangzhou, China. METHODS: A total of 5734 children aged 8-12 years from 29 schools completed self-report questionnaires, which included the Paediatric Quality of Life Inventory 4.0 for measuring HRQoL and Ma figural stimuli for measuring BD. Based on their level of BD, the children were divided into three groups: no dissatisfaction, mild dissatisfaction and moderate or high dissatisfaction. Based on the children's perceptions of their own body image, the groups were also categorized into just right, too fat and too thin groups. Height and weight were objectively measured using standardized methods, and a BMI z-score was derived using the age- and sex-specific WHO references from 2007 for children aged 5-19 years. Weight status was classified as underweight, healthy weight, overweight or obese. RESULTS: A total of 78.10% of children aged 8-12 years in Guangzhou had different levels of BD; boys had slightly higher levels BD than girls (p < 0.01), and obese children demonstrated the highest degree of BD (p < 0.01). However, BD levels did not differ significantly according to age (p = 0.194). Gender differences in body image perceptions were only found in children with a healthy weight (p < 0.01), but age differences in body image perception were present in both children with a healthy weight (p < 0.05) and underweight children (p < 0.05). Of the children with a healthy weight who were dissatisfied with their body image, 65.54% of the boys wanted to be heavier, whereas 52.95% of the girls wanted to be thinner (p < 0.01), and older children were more inclined to perceive themselves as too fat (p < 0.01). After controlling for the influence of confounding factors, significant trends for lower HRQoL scores with increasing BD levels persisted in all domains (p < 0.01). CONCLUSIONS: BD is as common in children as in adolescents and adults and might be independently associated with HRQoL impairment. The present findings suggest that the current epidemic of BD is a threat to the health of primary school children in China, and prevention programmes for this population should be implemented in the future.

Association between poor vision and time spent in outdoor activity of students in Guangzhou / 中国学校卫生

Objective@#To investigate the association of poor vision with time spent in outdoor activity among students from primary and middle schools, as well as from universities in Guangzhou, so as to provide targeted scientific basis for prevention and control of low vision.@*Methods@#According to the requirements of National Monitoring of Common Diseases and Health Risk Factors among Students Manual, a total of 2 908 students were selected in 1 urban area and 1 suburban county for monitoring and investigation in Guangzhou.@*Results@#The poor vision rate was 69.2% among students in Guangzhou, with girls (74.4%) > boys (64.2%), suburban country (76.3%) > urban areas (54.1%), university (95.0%) > vocational high school (82.5%) > regular high school (81.1%) > junior high school (73.4%) > primary school (45.6%). With the exception of primary students, the severe poor vision has the largest proportion in each age group. The proportion of spending less than 1 or 2 h for outdoor activities per day: girls>boys, suburban country > urban area, university and regular high school are higher. The poor vision rate of students who spent <2 h(72.3%) for outdoor activities daily was higher than those spent ≥2 h(65.6%). Compared with students who spent ≥2 h/d for outdoor activities, those spent < 2 h/d were at 1.24 times risk of being low vision(OR=1.24, 95%CI=1.04-1.48), controlling for the available confounders.@*Conclusion@#Poor vision rate of students in Guangzhou is high, occurring mainly with severe impairment and in younger age, the daily outdoor activity time is low. Girls, students from suburban country and junior high school should be considered as the emphasis for prevention and control of low vision.

[Physical activities and its influencing factors among students' parents in four cities in China, 2014].

OBJECTIVE: To study the status of physical activities and its influencing factors among parents of primary and secondary school students, to provide basis for improving students' parents physical activities. METHODS: A total of 12 501 parents ofprimary and secondary school students from Shenyang, Guangzhou, Chengdu and Wuhan were selected by stratified random cluster sampling. They completed a self-designed questionnaire that was derived from International Physical Activity Questionnaire( IPAQ). Logistic regression model was used to analyze the influence of region, stage of school, gender, age, education level, occupation and economic level on physical activities among parents of primary and secondary school students. RESULTS: The rate of students' parents with insufficient physical activity was 58. 3%, and the rate of students' parents spending2 h and more on sedentary activities per day was 55. 7%. Logistic regression analysis showed that compared with primary school students ' parents, the risk of insufficient physical activity and spending 2 h and more on sedentary activities of junior and senior middle school students' parents were decreased( the risk of insufficient physical activity:ORjunior( 95% CI) = 0. 796( 0. 728-0. 869), ORsenior( 95% CI) = 0. 746( 0. 683-0. 815); the risk of spending 2 h and more on sedentary activities: ORjunior( 95% CI) =0. 823( 0. 750-0. 904), ORsenior( 95% CI) = 0. 788( 0. 712-0. 872)). Compared with students' parents with primary school education, the risk of insufficient physical activity and spending 2 h and more on sedentary activities of parents with junior college or above education were increased( the risk of insufficient physical activity: OR( 95% CI) = 1. 288( 1. 107-1. 497); the risk of spending 2 h and more on sedentary activities: OR( 95%CI) = 1. 303( 1. 120-1. 515)). Compared with housework/unemployed/retirees, the risk of insufficient physical activity and spending 2 h and more on sedentary activities of agricultural/equipment operators were decreased( the risk of insufficient physical activity:OR( 95% CI) = 0. 755( 0. 634-0. 899); the risk of spending 2 h and more on sedentary activities: OR( 95% CI) = 0. 731( 0. 617-0. 867)). CONCLUSION: The rate of insufficient physical activity and spending 2 h and more on sedentary activities among students' parents were relatively higher. The influencing factors on physical activity level and sedentary activity time were region, stage of school, education level and occupation. Specific interventions should be developed for different people.

Analysis of influencing factors of dental caries in first permanent molars among children aged 10-12 years old in Guangzhou / 口腔疾病防治

Objective @# To know the influencing factors of dental caries in first permanent molars among children aged 10-12 years old in Guangzhou, and to give references for dental caries prevention.@*Methods @#The samples were selected by stratified random sampling method. Oral health examination and questionnaires were applied to all the 18 656 children who were 5 or 6-grade in 149 primary schools. @*Results @#The prevalence of dental caries in first permanent molars was 18.19%. Girls accouted for 19.96%, which was significantly higher than that of boys (16.71%) (χ2 = 32.817, P< 0.001). Multiple regression analyses were used to investigate the influencing factors of dental caries in first permanent molars. After controlling school cluster and other factors, household register, gender, pit and fissure sealant, consumption of sweets and chocolates, consumption of sweet milk were influencing factors of permanent teeth caries. And household register, gender, pit and fissure sealant, consumption of sweets and chocolates were associated with mean DMFT.@*Conclusion @#school oral health education should focus on the consumption of sugars and cares should be put into the differences between urban and rural area. In addition, strengthening publicity of the sealant retention project,raising public awareness, and improving sealant retention quality are necessary to ensure the anti-caries effect.