Regarding the importance of air pollution issue for large cities, as Tehran metropolis, many plans, programs, projects and regulations have been developed to manage urban air pollution. However, most of them failed to decline the pollution. The purpose of this study is to pathologically analyze air-pollution control plans in order to offer effective solutions for Tehran metropolis.
A qualitative content analysis and a semi-structured interview with 14 practicing professionals were used to identify key causes and sources of Tehran's air pollution, to recognize challenges and obstacles towards effective performance of air-pollution control plans in this metropolitan area, and to suggest the most effective controlling solutions.
Challenges related to air-pollution control plans can be divided into two major categories: Firstly lack of integrated and organized stewardship and secondly those related to political, economical, social and technical environmental abbreviated as PEST, challenges. For effective control of the Tehran air pollution, the following eight controlling alternatives were identified: Systematization of plan preparation process, organizing the stewardship, standardization and utilization of new technologies and professional experts, cultural and infrastructural development, realization of social justice, developing coordination and controlling mechanisms, improving citizen's participatory capacity, and focusing on effective management of fuel and energy.
Controlling air pollution in Tehran should be considered as a priority for policymakers to make enforcements through applying a systemic cycle of preparation effective and comprehensive plans. Further, implement the enforcements and evaluate the environmental impact of the plans through involving all stakeholders.
Air pollution management; control plan; pollutants; public health
Introduction. This study aims to assess the factors associated with 25-hydroxy vitamin D (25(OH)D) levels in pregnant women and their newborns in a sunny region. Materials and Methods. This cross-sectional study was conducted in 2012 in Isfahan, Iran. It comprised 100 nulliparous singleton pregnant women, selected by random cluster sampling. Laboratory tests were assessed before delivery in mothers and after delivery in their infants' umbilical cord blood. The P for trend of variables was assessed across the air quality index (AQI) quartiles. The associations of AQI and 25(OH)D were assessed by multiple linear regression after adjustment for age, body mass index, and dietary intake. Results. Sera of 98 mothers and an equal number of newborns were analyzed. The median (interquartile range, IQR) of serum 25(OH)D of mothers and neonates was 15.1(12.6, 18.2) ng/mL in mothers and 15.7(12.0, 18.1) ng/mL in neonates, respectively. AQI had an inverse association with serum 25(OH)D (Beta = −0.58, P = 0.04). The corresponding figure was also inverse and significant for newborns (Beta (SE)= −0.51(0.04), P = 0.01). Conclusion. The independent inverse association of 25(OH)D with air quality can explain the high prevalence of hypovitaminosis D in pregnant women living in this sunny region.
The purpose of this paper is to systematically review the experimental and human studies on obesogenic chemicals and their mechanisms of action to provide a comprehensive view on the multifactorial aspects of obesity. The literatures were searched in available databases. The relevant papers were selected in three phases. After quality assessment, two reviewers extracted the data while another checked their extracted data. In this review, we summarized information regarding environmental chemicals that can be associated with obesity. Most evidence comes from experimental and laboratory studies; however a growing number of human studies also support the role of obesogenic chemicals. The current evidence proposes that the systemic responses to exposure to environmental factors could potentially increase the risk of excess weight. The effects of exposure to these chemicals are of crucial importance during developmental phases of life, when preprogramming for an adipogenic outcome may occur. By considering the adverse transgenerational effects of obesogen chemicals on human health, the global obesity epidemic should be considered as a multifactorial complex disorder necessitating the emphasis of public health interventions for environmental protection.
Introduction. This study aimed to determine the association of blood cadmium level with cardiometabolic risk factors and liver enzymes in adolescents. Methods. This case control study comprised 320 Iranian adolescents, 160 with metabolic syndrome and an equal number of controls. They were selected from participants of a nationwide survey entitled the CASPIAN-III study. Cadmium was measured by atomic absorption method. Results. The mean age of the case and control groups was not significantly different (15.3 ± 2.6 versus 14.63 ± 2.5 years, resp., P > 0.05). The mean cadmium level was near double-fold higher than the standards of the World Health Organization, without significant difference between the MetS and control groups (10.09 ± 2.21, 9.97 ± 2.38 μg/L, resp., P > 0.05). Cadmium level had positive but nonsignificant correlations with diastolic blood pressure, serum triglycerides, fasting blood glucose, LDL-C, and liver enzymes. Conclusion. Cadmium level had positive but nonsignificant association with some cardiometabolic risk factors and liver enzymes. The associations did not reach statistical significant level, and this may be because of the high levels of cadmium in both groups studied or because of the young age group of participants. Controlling environmental pollutants shall be a priority for the prevention of chronic diseases.
This study explores the associations of weight perceptions with actual body mass index (BMI) and attempts to lose weight in a nationally representative sample of a pediatric population.
Material and methods
Data were collected from school students of 27 provinces in Iran, as part of “the national survey of school student high risk behaviors”. We used t-test for continuous data and chi square test for categorical data. The correlation between categorical variables was assessed by Cramer's phi test. A multiple nominal logistic regression model was fitted to data to assess the association between perceived body weight and gender by adjusting for potential confounding variables.
The study participants consisted of 5570 (2784 girls, 70% urban) students with mean age of 14.7 ±2.4 years. Overall, 17.3% of students were underweight, and 17.7% were overweight or obese. Nearly 25% and 50% of participants reported themselves as appropriate weight and very obese, respectively. In both genders, the strength of association between perceived weight and actual BMI was quite high (Cramer's phi coefficient = 0.5, p < 0.0001), and that of perceived body weight with trying to lose weight was moderate (Cramer's phi coefficient = 0.2, p < 0.0001). Overweight students were more likely than their obese peers to try to lose weight. After adjusting for possible confounders, the chance of perceiving oneself as very obese compared to perceiving oneself as very thin was 1.56-fold higher in girls than in boys, i.e. OR (95% CI): 1.56 (1.27-1.91).
This study revealed a considerably frequent “mismatch” between actual weight status and body shape dissatisfaction, which supports the necessity of increasing public awareness in this regard.
perceived overweight; weight loss; body image; children and adolescents
Objective. We aimed to investigate the amounts of nitrate, nitrite, and total organic carbon (TOC) in two drinking water sources and their relationship with some gastrointestinal diseases. Methods. This cross-sectional study was conducted in 2012 in Iran. Two wells located in residential areas were selected for sampling and measuring the TOC, nitrate (NO3−), and nitrite (NO2−). This water is used for drinking as well as for industrial and agricultural consumption. Nitrate and nitrite concentrations of water samples were analyzed using DR 5000 spectrophotometer. The information of patients was collected from the records of the main referral hospital of the region for gastrointestinal diseases. Results. In both areas under study, the mean water nitrate and nitrite concentrations were higher in July than in other months. The mean TOC concentrations in areas 1 and 2 were 2.29 ± 0.012 and 2.03 ± 0.309, respectively. Pollutant concentration and gastrointestinal disease did not show any significant relationship (P > 0.05). Conclusion. Although we did not document significant association of nitrite, nitrate, and TOC content of water with gastrointestinal diseases, it should be considered that such health hazards may develop over time, and the quality of water content should be controlled to prevent different diseases.
To determine inequality in mortality in 1-59 months children across Iranian provinces focusing on referring system and determinants of death.
After designing and examining a national questionnaire for mortality data collection of children 1-59 months, 40 medical universities have been asked to fill in the questionnaires and return to the main researcher in the health ministry in 2009.
Mortality in 1-59 months children was unequally distributed across provinces (universities). The recommended refer was 3466 but only 1620 patients were referred. The first five important determinants of death were congenital (671 children or 20.9%), accident (547 children or 17.1%), pulmonary diseases (370 children or 11.5%), cardiovascular (266 children or less than 8.3%), central nervous system (263 children or 8.2%), and infectious and parasitic diseases (245 children or 7.6%), respectively.
Our results suggest that inequality in 1-59 months mortality based on the hospital records, and specially referring system, needs more attention in Iran. In addition, it is advisable to conduct provincially representative surveys to provide recent estimates of hospital access inequalities and to allow monitoring over time.
Children mortality; hospital records; Iran; national mortality registration system; referring system
To assess the national inequality of school readiness and autism among 6-year-old Iranian children before school entry using a national health assessment survey.
In a cross-sectional nationwide survey, all Iranian children entering public and private elementary schools were asked to participate in a mandatory national screening program in Iran in 2009 in two levels of screening and diagnostic levels.
The study population consisted of 955388 children (48.5% girls and 76.1% urban residents). Of the whole children, 3.1% of the 6-year-old children had impaired vision. In addition, 1.2, 1.8, 1.4, 7.6, 0.08, 10, 10.9, 56.7, 0.7, 0.8 and 0.6 percent had color blindness, hearing impaired, speech disorder, school readiness, autism, height to age retardation, body mass index extremes, decayed teeth, disease with special needs, spinal disorders, and hypertension, respectively. The distribution of these disorders was unequally distributed across provinces.
Our results confirmed that there is an inequality in distribution of school readiness and autism in 6-year-old children across Iranian provinces. The observed burden of these distributions among young children needs a comprehensive national policy with evidence-based province programs to identify the reason for different inequality among provinces.
National Health Assessment Survey; School Readiness; Autism; Children; Inequality; Iran
By the current global obesogenic environment, non-alcoholic fatty liver disease is becoming an important health problem in the pediatric age group.
This study aimed to determine the first age-and gender-specific percentiles and upper limit normal limit (ULN) of alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST) among a nationally-representative sample of children and adolescents in the Middle East and North Africa (MENA). The second objective was to determine the linear association of obesity indexes and age with serum ALT and AST levels.
Patients and Methods
This nationwide study was conducted among a representative sample of 4078 students aged 10-18 years, who were selected by multistage random cluster sampling from 27 provinces of Iran. ALT and AST were measured on fresh sera. Body mass index (BMI) was calculated as an index of generalized obesity, and waist- to- height ratio (WHtR) as an index of abdominal obesity. The age- and gender-specific percentiles of ALT and AST were constructed, and the 95th percentile of each enzyme was considered as the ULN. Gender-specific linear regression analysis was employed to examine the association of BMI or WHtR with the levels of ALT and AST.
Data of ALT and AST were available for 4078 (2038 girls) and 4150 (2061 girls),respectively. Participants had a mean (SD) age of 14.71 (2.41).The ULN of ALT for boys, girls,and the total individuals were 36.00; 38.00; and, 37.00 U/L, respectively. In both genders, ALT and AST had linear association with age. The association with BMI was significant for ALT in both genders and for AST only in boys, the association of ALT with WHtR was significant in both genders; the corresponding figures were not significant for AST.
The findings of the current study confirmed the current ULN value of 40 U/L commonly used for the pediatric age group. The linear association of indexes for generalized and abdominal obesity with ALT underscores the importance of timely prevention and control of childhood obesity.
Aminotransferase; Child; Iran
Little experience exists on valid and reliable tools for assessment of the determinants of underweight and overweight in children and adolescents living in the Middle-East and North Africa (MENA). This study aimed to develop a valid and wideranging questionnaire for assessment of these parameters in a nationwide sample of Iranian children and adolescents.
This national study was conducted in 31 provinces in Iran. The first phase consisted of focus group discussion with 275 children and adolescents and their parents. After a qualitative content analysis, the initial items were extracted. In the next step, the face validity was assessed by expert panelists using the quantitative method of the Impact Score. To assess the content validity, the content validity rate (CVR) and the content validity index (CVI) were determined. The internal consistency was examined by Cronbach alpha, and its test-retest reliability was determined. The socio-demographic variables, perinatal factors, lifestyle factors, family history, knowledge and attitude were assessed. Dietary intakes were assessed by a validated 168-item semi-quantitative food frequency questionnaire. A validated questionnaire for quality of life was filled in anonymously.
A team of expert researchers conducted the data analysis of 576 interviews by using qualitative content analysis method. The analysis process began by determining the semantic units about the concepts studied. The initial questionnaire was developed in four domains by including Likert scale questions. In the face validity step, all questions of the primary questionnaire obtained a score of more than 1.5. In the phase of CVR assessment, 6 questions obtained a score of less than 0.62, and were omitted. The rest of questions were assessed for CVI, and got a score of more than 0.75. Cronbach's alpha coefficient of the whole questionnaire was 0.97, and the Pearson correlation coefficient of the test-retest phase was 0.94.
The developed questionnaire is a valid and reliable tool for assessment of the determinants of weight disorders in a nationally representative sample of children and adolescents in the MENA.
Children and adolescents; overweight; questionnaire validity; underweight
The World Health Organization (WHO) is in the process of establishing a new global database on the growth of school children and adolescents. Limited national data exist from Asian children, notably those living in the Middle East and North Africa (MENA). This study aimed to generate the growth chart of a nationally representative sample of Iranian children aged 10–19 years, and to explore how well these anthropometric data match with international growth references.
In this nationwide study, the anthropometric data were recorded from Iranian students, aged 10–19 years, who were selected by multistage random cluster sampling from urban and rural areas. Prior to the analysis, outliers were excluded from the features height-for-age and body mass index (BMI)-for-age using the NCHS/WHO cut-offs. The Box-Cox power exponential (BCPE) method was used to calculate height-for-age and BMI-for-age Z-scores for our study participants. Then, children with overweight, obesity, thinness, and severe thinness were identified using the BMI-for-age z-scores. Moreover, stunted children were detected using the height-for-age z-scores. The growth curve of the Iranian children was then generated from the z-scores, smoothed by cubic S-plines.
The study population comprised 5430 school students consisting of 2312 (44%) participants aged 10–14 years , and 3118 (58%) with 15–19 years of age. Eight percent of the participants had low BMI (thinness: 6% and severe thinness: 2%), 20% had high BMI (overweight: 14% and obesity: 6%), and 7% were stunted. The prevalence rates of low and high BMI were greater in boys than in girls (P < 0.001). The mean BMI-for-age, and the average height-for-age of Iranian children aged 10–19 years were lower than the WHO 2007 and United states Centers for Disease Control and Prevention 2000 (USCDC2000) references.
The current growth curves generated from a national dataset may be included for establishing WHO global database on children’s growth. Similar to most low-and middle income populations, Iranian children aged 10–19 years are facing a double burden of weight disorders, notably under- and over- nutrition, which should be considered in public health policy-making.
Growth; Iran; Reference curve; Weight disorder
The aim of our study was to determine the content of fat and fatty acid composition of breast milk, and its association with the mother’s diet.
Materials and Methods:
This cross-sectional study was conducted among pregnant mothers who came to health care centers for last prenatal care in Isfahan, Iran. Eight to 72 hours after delivery, 2 to 5 ml of colostrum was collected by hand into tubes. They were kept in an ice box and sent within half an hour to the collaborating health centre for freezing at -20°C until analysis, which was performed at the laboratory of NNFTRI in Tehran. The milk samples were homogenized by Vortex (Heidolph Vortex Shaker REAX 1. 220 V. 30 W Germany) at 2400 rpm for 30 sec.
The data of 86 out of 91 samples were complete. The mean maternal age and gestational age was 28.37 ± 5.55 years old and 38.7 ± 1.2 weeks, respectively. The content of fat was 2.17 ± 1.22 g/100 ml breast milk. Arachidonic acid (AA, 20:4n-6) and docosohexaanoic acid DHA (22:6n-3) made 0.8 ± 0.4% and 0.3 ± 0.2% of total fatty acids. Although the AA/DHA ratio in our study is suitable, but the content of DHA is nearly low.
Dietary habits of women in reproductive age group should be improved, with special emphasis on the fatty acid content of breast milk. This may have long-term impact on health promotion and disease prevention.
Breast milk; fatty acid; Iran; neonate; pregnancy
This study aims to determine the association of some genetic polymorphisms in the relationship of air pollutants on the serum levels of thrombomodulin (TM) and tissue factor (TF) in a population-based sample of children and adolescents.
Materials and Methods:
This cross-sectional study was conducted among 110 participants (52.8% girls) with a mean age of 12.7 + 2.3 years, in Isfahan, Iran. Genotypes of TM G33-A and + 5466A > G polymorphisms were determined by the polymerase chain reaction – restriction length fragment polymorphism method (PCR-RFLP). The enzyme-linked immunosorbent assay (ELISA) was used for measurement of serum TM and TF.
The following genotypes were identified for TM: GG in 69.2%, GA in27.2%, and AA in 3.6% of the participants. Considering TF, 108 participants were homozygous for the + 5466A allele, and two subjects had + 5466AG genotype. The mean pollution standards index (PSI) value was at a moderate level; the mean particulate matter measured up to 10 μm (PM10); and ozone (O3), nitrogen dioxide, and sulfur dioxide were considerably high. The mean serum TF and TM levels were not significantly different among the participants with the aforementioned genotypes. Among participants exposed to high quartiles of O3, PM10, and PSI, the TM-33G / A polymorphism (GA + AA genotype) increased the Odds ratio (OR) of the low serum TM level. There was no statistically significant association in the areas of low pollution.
The findings of our study support the synergistic effect of the TM-33G / A polymorphism and air pollutants on factors associated with the onset of the atherosclerosis. This might be confirmatory evidence for gene-environment interaction, and related effects on atherogenesis from early life.
Air pollution; atherosclerosis; children; genetics; prevention
To assess the national prevalence of clinical disorders in 6-year-old Iranian children before school entry using a national health assessment survey.
Materials and Methods:
In a cross-sectional nationwide survey, all Iranian children entering public and private elementary schools were asked to participate in a mandatory national screening program in Iran in 2009 in two levels of screening and diagnostic levels.
The study population consisted of 955388 children (48.5% girls and 76.1% urban). Of the whole children, 3.1% of the 6-year-old children had impaired vision. In addition, 1.2, 1.8, 1.4, 10, 10.9, 56.7, 0.7, 0.8 and 0.6% had color blindness, hearing impaired, speech disorder, height to age retardation, body mass index extremes, decayed teeth, having disease with special needs, spinal disorders, and hypertension, respectively. The distribution of these disorders was unequally distributed across provinces.
Our results confirmed that the prevalence of clinical disorders among 6-year-old children across Iranian provinces was not similar. The observed burden of these distributions among young children needs a comprehensive national policy with evidence-based province programs to identify the reason for different distribution among provinces.
Children; clinical symptoms; Iran; national health assessment survey; prevalence
A school-based surveillance system entitled the childhood and adolescence surveillance and prevention of Adult Noncommunicable disease (CASPIAN) Study is implemented at national level in Iran. This paper presents the methods and primary findings of the third survey of this surveillance system.
This national survey was performed in 2009–2010 in 27 provinces of Iran among 5570 students and one of their parents. In addition to physical examination, fasting serum was obtained. Body mass index was categorized based on the World Health Organization growth charts.
Data of 5528 students (2726 girls, 69.37% urban, mean age 14.7 ± 2.4 years) were complete and are reported. Overall, 17.3% (17.3% of girls and 17.5% of boys) were underweight, and 17.7% (15.5% of girls and 19.9% of boys) were overweight or obese. Abdominal obesity was documented in 16.3% of students (17.8% of girls and 15% of boys). 57.6% of families consumed breads, the staple food for Iranians, prepared with white flour. Most families (43.8% in urban areas and 58.6% in rural areas) used solid hydrogenated fats. 22.7% of students did not add salt to the table food. 14.2% of students reported to have a regular daily physical activity for at least 30 min a day. Overall, 10.4% of students (11.7% in urban areas and 7.3% in rural areas) reported that they used tobacco products, often waterpipe. 32.8% of students experienced at least three times of bullying in the previous 3 months. During the year prior to the survey, 14.46% of students had an injury needing the interference by school health providers.
This survey is confirmatory evidence on the importance of establishing surveillance systems for risk behaviors to implement action-oriented interventions.
Chronic diseases; prevention; risk behaviors; risk factors; school health; surveillance
This study aimed to determine the association of particulate matters with endothelial function, measured by flow mediated dilation (FMD) of brachial artery, in children with or without exposure to secondhand smoke.
This cross-sectional study was conducted from January to March 2011 in Isfahan, which is the second large and air-polluted city in Iran. The areas of the city with lowest and highest air pollution were determined, and in each area, 25 prepubescent boys with or without exposure to daily tobacco smoke in home were selected, i.e. 100 children were studied in total.
FMD was significantly smaller in those living in high-polluted area and those exposed to secondhand smoke. Multiple linear regression analysis, adjusted for age and body mass index, showed that both passive smoking status and living area in terms of particulate air pollution were effective determinants of the brachial artery diameter. The standardized coefficient of passive smoking status was –0.36 (SD = 0.09, P < 0.0001) showing negative association with percent increase in FMD. Likewise, the percent increase in brachial artery diameter was lower in passive smoker children. Similar relationship was documented for PM10 concentration with a regression coefficient of –0.32 (SD = 0.04, P < 0.0001). Without considering passive smoking variable, PM10 concentration has significant independent effect on FMD level.
Our findings provide evidence on the association of environmental factors on endothelial dysfunction from early life. Studying such associations among healthy children may help identify the underlying mechanisms. The clinical implications of environmental factors on early stages of atherosclerosis should be confirmed in longitudinal studies.
Air pollution; children; endothelium-dependent brachial artery; smoke
Malignancies are primarily environmental diseases mostly attributed to environmental factors. By plotting the prevalence and spatial distribution maps, important differences can be observed in detail. This study aimed to determine the association between map distribution of malignancies and the geological phenomena of lead (Pb) accumulation in soil in the province of Isfahan, Iran.
Spatial distribution maps of malignant diseases were plotted by using data recorded during 2007 to 2009 in the Isfahan Cancer Registry Program. Data on Pb accumulation in soil was obtained from the National Geological Survey and Mineral Exploration. Pb concentrations were documented in three parts of agricultural, non-agricultural, urban, and industrial land. The geographical mapping of cancers and soil Pb were then incorporated into a geographic information system (GIS) to create a spatial distribution model.
The spatial distributions of ten common malignant diseases in the province, i.e. skin cancers, hematological malignancies, and breast cancers, followed by other malignancies were scattered based on Pb distribution. In fact, common cancers were more prevalent in the parts of the province where soil Pb was more abundant.
The findings of this study underscore the importance of preventing Pb exposure and controlling industrial production of Pb. The data is also important to establish further effects modeling for cancers. Moreover, physicians and health professionals should consider the impact of environmental factors on their patients’ health.
Environment; Cancers; Lead; Spatial Distribution; Iran
Objective. To determine the most effective and biodegradable dispersant of spilled oil in water surrounding two Persian Gulf provinces. Methods. This study compared the effects of three dispersants, Pars 1, Pars 2, and Gamlen OD4000 on removal of oil in two Persian Gulf provinces' water. Overall, 16 stations were selected. Using the Well method, the growth rate of isolated bacteria and fungi was identified. To specify the growth rate of microorganisms and their usage of oil in the presence of the above-mentioned dispersants, as exclusive sources of carbon, the bacteria were grown in culture medium for 28 days at 120 rpm, 30°C, and their optical density was measured by spectrophotometry. Then, we tested biological oxygen demand (BOD) and chemical oxygen demand (COD) in microorganisms. Results. The highest growth rate was documented for the growth of microorganisms on either Pars 1 or Pars 2 dispersants or their mixtures with oil. However, the culture having microorganisms grown on Pars 1 had higher BOD and COD than the other two dispersants (9200 and 16800 versus 500 and 960, P < 0.05). Mixture of oil and Pars 2 as well as oil and Pars 1 dispersants showed the highest BODs and CODs, respectively. In the Bahregan province, microorganisms grown on Pars 2 had maximum amount of BOD and COD in comparison with Pars 1 and Gamlen dispersants (7100 and 15200 versus 6000 and 10560, P < 0.05). Conclusion. Pars 1 and Pars 2 were the most effective dispersants with highest degradability comparing Gamlen. In each region, the most suitable compound for removing oil spill from offshores with least secondary contamination should be investigated.
Background. The purpose of this study is environmental impact assessment of the industrial estate development planning. Methods. This cross-sectional study was conducted in 2010 in Isfahan province, Iran. GIS and matrix methods were applied. Data analysis was done to identify the current situation of the region, zoning vulnerable areas, and scoping the region. Quantitative evaluation was done by using matrix of Wooten and Rau. Results. The net score for impact of industrial units operation on air quality of the project area was (−3). According to the transition of industrial estate pollutants, residential places located in the radius of 2500 meters of the city were expected to be affected more. The net score for impact of construction of industrial units on plant species of the project area was (−2). Environmental protected areas were not affected by the air and soil pollutants because of their distance from industrial estate. Conclusion. Positive effects of project activities outweigh the drawbacks and the sum scores allocated to the project activities on environmental factor was (+37). Totally it does not have detrimental effects on the environment and residential neighborhood. EIA should be considered as an anticipatory, participatory environmental management tool before determining a plan application.
Non-alcoholic fatty liver disease (NAFLD) is becoming as an important health problem in the pediatric age group. In addition to the well-documented role of obesity on the fatty changes in liver, there is a growing body of evidence about the role of environmental factors, such as smoking and air pollution, in NAFLD. Given that excess body fat and exposure to air pollutants is accompanied by systemic low-grade inflammation, oxidative stress, as well as alterations in insulin/insulin-like growth factor and insulin resistance, all of which are etiological factors related to NAFLD, an escalating trend in the incidence of pediatric NAFLD can be expected in the near future. This review focuses on the current knowledge regarding the epidemiology, diagnosis and pathogenesis of pediatric NAFLD. The review also highlights the importance of studying the underlying mechanisms of pediatric NAFLD and the need for broadening efforts in prevention and control of the main risk factors. The two main universal risk factors for N LD, obesity and air pollution, have broad adverse health effects, and reducing their prevalence will help abate the serious health problems associated with pediatric NAFLD.
Fatty Liver; Child; Obesity; Environmental Exposure; Prevention and Control; Air Pollution
Pediatric pre-hypertension (pre-HTN) has a complex multifactorial etiology. Although most cases are secondary to other disorders, a substantial number of children and adolescents have primary or essential HTN and pre-HTN. The gene-gene and gene-environment interactions should be considered in this context. The strong relationship of pre-HTN with environmental factors such as air pollution, noise pollution and passive smoking and obesity suggest that its prevalence will be escalating.
Exposure to ambient particulate matters may increase blood pressure (BP) within hours to days. The underlying biologic pathways include autonomic nervous system imbalance and arterial vascular dysfunction or vasoconstriction because of systemic oxidative stress and inflammation. Likewise, tobacco smoke exposure of pregnant mothers increases systolic BP of their offspring in early infancy. Parental smoking also independently affects systolic BP among healthy preschool children. Noise exposure, notably in night, is associated with catecholamine secretion, increased BP and a pre-HTN state even in pre-school age children.
Excess weight is associated with dysfunction of the adipose tissue, consisting of enlarged hypertrophied adipocytes, increased infiltration by macrophages and variations in secretion of adipokines and free fatty acids. These changes would result in chronic vascular inflammation, oxidative stress, activation of the renin-angiotensin-aldosterone system and sympathetic response, and ultimately to pre-HTN from childhood.
Prevention and control of the modifiable risk factors of pre-HTN from prenatal period can have long-term health impact on primordial and primary prevention of chronic non-communicable diseases. This review presents a general view on the diagnosis, prevalence and etiology of pre-HTN along with practical measures for its prevention and control.
Prevention; Blood Pressure; Pre-hypertension; Genetics; Environment; Children
This study aimed to determine the secular trends in the national prevalence of overweight and obesity among 6-year-old Iranian children, and to compare the results in Northern, Central and Southern parts of the country.
The data were collected as part of a routine and mandatory national screening program on children entering elementary schools in 2007, 2008 and 2009.
The study population comprised 2,600,065 children including 862,433 in 2007, 782,244 in 2008 and 955,388 in 2009. Of total children 12.8%, 13.5% and 10.9% were overweight in 2007, 2008 and 2009, respectively (P > 0.05). The corresponding figures for obesity were 3.4%, 3.5% and 3.4%, respectively (P > 0.05). In all surveys, the prevalence of overweight was higher in Southern region than in the other two regions. P for trend was not significant for prevalence rates of overweight and obesity in any of the regions.
To the best of our knowledge, this study was the first of its kind in presenting the nationwide trend of overweight and obesity in young children living in a developing country. It showed a considerably high prevalence of overweight and obesity, but with a constant rate in three years. The higher prevalence of overweight in Southern region than in Central and Northern regions might be related to the lower socioeconomic position of this population. At a very young age, children's lifestyle is more under control of parents. Primordial and primary prevention efforts against the overweight epidemic can be effective and shall be further strengthened.
Prevalence; Trend; Overweight; Children; National Study; Iran
The purpose of this study was to assess the effects of exercise on the aerobic power, serum lactate level, and cell blood count among active individuals in the environments with similar climatic characteristics differing in their level of air pollution.
This trial comprised 20 volunteer students of Physical education in The University of Isfahan, Iran. Two places with the same climate (altitude, temperature, and humidity), but low and high level of air pollutants air were selected in Isfahan, Iran. Participants underwent a field Cooper test with a 12-minute run for fitness assessment. Then the aerobic power, serum lactate, and cell blood counts were measured and compared between the two areas.
The study participants had a mean (SD) age of 21.70 (2.10) years and body mass index (BMI) of 24.44 (2.32) Kg/m2. We found a significant decrease in mean Vo2 max, red blood cell count, hemoglobin, hematocrit, and mean corpuscular hemoglobin, as well as significant increase in mean lactate level, white blood cell count and mean corpuscular volume in the higher-polluted than in the lower-polluted area. No significant difference was documented for other parameters as platelet counts or maximum heart rate.
Exercise in high-polluted air resulted in a significant reduction in the performance at submaximal levels of physical exertion. Therefore, the acute exposure to polluted air may cause a significant reduction in the performance of active individuals. The clinical importance of these findings should be assessed in longitudinal studies.
Air pollution; Aerobic power; Lactate; Active individuals
Health professionals face the adverse health effects of climate change and air pollution in their practices. This review underscores the effects of these environmental factors on maternal and children's health, as the most vulnerable groups to climate change and air pollution.
We reviewed electronic databases for a search of the literature to find relevant studies published in English from 1990 to 2011.
Environmental factors, notably climate change and air pollution influence children's health before conception and continue during pregnancy, childhood, and adolescence. Experts have suggested that such health hazards may represent the greatest public health challenge that humanity has faced. The accumulation of greenhouse gases such as carbon dioxide, primarily from burning fossil fuels, results in warming which has an impact on air pollution particularly on levels of ozone and particulates. Heat-related health effects include increased rates of pregnancy complications, pre-eclampsia, eclampsia, low birth weight, renal effects, vector-borne diseases as malaria and dengue, increased diarrheal and respiratory disease, food insecurity, decreased quality of foods (notably grains), malnutrition, water scarcity, exposures to toxic chemicals, worsened poverty, natural disasters and population displacement. Air pollution has many adverse health effects for mothers and children. In addition to short-term effects like premature labour, intrauterine growth retardation, neonatal and infant mortality rate, malignancies (notably leukaemia and Hodgkin lymphoma), respiratory diseases, allergic disorders and anaemia, exposure to criteria air pollutants from early life might be associated with increase in stress oxidative, inflammation and endothelial dysfunction which in turn might have long-term effects on chronic non-communicable diseases.
Health professionals have an exclusive capability to help prevent and reduce the harmful effects of environmental factors for high-risk groups, and should consider this capacity in their usual practice.
Climate change; air pollution; health; health professionals; pregnant mothers; children; prevention