Cooking oil fume exposure and Lung-RADS distribution among school cafeteria workers of South Korea.

Background: Cooking oil fumes (COFs) from cooking with hot oil may contribute to the pathogenesis of lung cancer. Since 2021, occupational lung cancer for individual cafeteria workers has been recognized in South Korea. In this study, we aimed to identify the distribution of lung-imaging reporting and data system (Lung-RADS) among cafeteria workers and to determine factors related to Lung-RADS distribution. Methods: We included 203 female participants who underwent low-dose computed tomography (LDCT) screening at a university hospital and examined the following variables: age, smoking status, second-hand smoke, height, weight, and years of service, mask use, cooking time, heat source, and ventilation. We divided all participants into culinary and non-culinary workers. Binomial logistic regression was conducted to determine the risk factors on LDCT of Category ≥ 3, separately for the overall group and the culinary group. Results: In this study, Lung-RADS-positive occurred in 17 (8.4%) individuals, all of whom were culinary workers. Binary logistic regression analyses were performed and no variables were found to have a significant impact on Lung-RADS results. In the subgroup analysis, the Lung-RADS-positive, and -negative groups differed only in ventilation. Binary logistic regression showed that the adjusted odds ratio (aOR) of the Lung-RADS-positive group for inappropriate ventilation at the workplace was 14.89 (95% confidence interval [CI]: 3.296-67.231) compared to appropriate ventilation as the reference, and the aOR for electric appliances at home was 4.59 (95% CI: 1.061-19.890) using liquid fuel as the reference. Conclusions: The rate of Lung-RADS-positive was significantly higher among culinary workers who performed actual cooking tasks than among nonculinary workers. In addition, appropriate ventilation at the workplace made the LDCT results differ. More research is needed to identify factors that might influence LDCT findings among culinary workers, including those in other occupations.

Effect of PM concentration on anemia blood indicators reduced by air purifiers.

Housewives perform daily household chores, which directly expose them to indoor particulate matter (PM). Indoor PM exposure is a potential factor that increases systemic inflammation and affects hematopoietic action. This study investigated the decrease in indoor PM concentration by air purifiers on indicators of anemia, such as hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). We analyzed the data of 40 housewives who were subjected to an air purifier intervention in Seoul and Ulsan, Republic of Korea. Indoor exposure levels of PM2.5 and PM10 were analyzed with sensor adjusted and gravimetric measurement. We also investigated the same anemia indicators before and after the installation of an air purifier for three months (short-term: one month, long-term: three months). Statistical analysis was performed by a multiple linear model and a linear mixed model. The indoor PM exposure levels and air purifier use were related to anemia indicators (hemoglobin and MCHC). The increase in indoor PM2.5 level was associated with a decrease in MCHC (ß: 0.034, P = 0.031) and hemoglobin (ß: 0.013, P = 0.04). The decrease in indoor PM2.5 concentration by air purifier was associated with an increase in MCHC (ß: 0.204, P = 0.087) and hemoglobin (ß: 0.190, P = 0.039). In particular, after air purifier intervention, the amounts of MCHC and hemoglobin significantly increased. Our results suggest that indoor air purifier use could decrease indoor PM level and the risk of anemia to housewives. Because the effect on anemia is subacute, it was confirmed three months after air purifier operation. In conclusion, anemia indicators can be improved by PM reduction management.

Association of paternal cadmium and other heavy metal exposure to birth outcomes using propensity score matching.

BACKGROUND: Human exposure to cadmium has various effects on health, especially on male reproductive organs. Although it is widely known that prenatal maternal cadmium exposure can affect birth outcomes, the effect of paternal exposure to cadmium remains unclear. OBJECTIVES: This study aimed to evaluate the effect of paternal cadmium exposure on fetal growth by considering maternal cadmium exposure and exposure to other heavy metals, namely mercury and lead. METHODS: The Mothers and Children's Environmental Health (MOCEH) study is a prospective birth cohort study in Korea. Overall, 1313 families (father-mother-child triple) without child abnormalities and who completed paternal whole blood cadmium assessments were included in this study. Families were divided into two subgroups based on the blood sampling periods, namely early and late pregnancy. Subjects were selected as follows: one family triple with a high level of paternal cadmium and two triples with low levels of paternal cadmium, using the method of propensity score matching. And linear regression analyses were performed. RESULTS: The group with high paternal cadmium exposure (80% or more; 1.93 µg/L) had lower birth weight infants compared to the group with low cadmium concentrations (ß(se) = -0.21(0.10); p-value = 0.0283). After stratification by infant sex, prenatal paternal cadmium exposure significantly reduced the birth weight of females in subgroups of different sampling times, namely early pregnancy (ß(se) = -0.52 (0.22); p-value = 0.0170) and late pregnancy (ß(se) = -0.43 (0.18); p-value = 0.0160). Finally, after performing propensity score matching in the early pregnancy measurement group, it was found that the prenatal exposure of father to cadmium significantly reduced birth weight in females (ß(se) = -0.72(0.25); p-value = 0.0047). CONCLUSION: This study assessed the effect of paternal cadmium exposure on birth outcomes in family units consisting of a father, mother, and child. Prenatal paternal cadmium exposure negatively affected birth weight, especially that of female, considering covariates and other heavy metals exposure, namely mercury and lead.

Acute lung injury in a worker after inhalation of ethylene phosphorodifluoridite.

Ethylene phosphorodifluoridite (C2H4F4O2P2) (CAS No. 3965-00-2) is a colorless corrosive fuming liquid that is used as a stabilizer in the electrolyte of rechargeable batteries. There are no previous reports of toxic effects following exposure to this compound. A 28-year-old male complained of respiratory distress after accidental inhalation of ethylene phosphorodifluoridite for 30 min. The patient developed acute lung injury with noncardiogenic pulmonary edema and was treated with supportive management. The patient fully recovered and was discharged after 7 days without any significant sequelae. The patient's symptoms were attributed to non-cardiogenic pulmonary edema caused by ethylene phosphorodifluoridite exposure. The case study showed that ethylene phosphorodifluoridite should be added to the list of chemicals that can cause acute lung injury. Int J Occup Med Environ Health. 2022;35(3):361-6.

Association of Participation in Health Check-ups with Risk Factors for Cardiovascular Diseases.

BACKGROUND: We compared the risk factors for cardiovascular diseases (CVDs) among Koreans who did and did not participate in national periodic health check-ups, after adjustment for demographic factors, socioeconomic status, and lifestyle factors. METHODS: This cross-sectional study used data from the Korea National Health and Nutrition Examination Survey (KNHANES) from 2007 to 2018. Study subjects were classified as participants or non-participants in health check-ups, based on attendance at national periodic health check-ups during the previous two years. RESULTS: Comparison of participants and non-participants in health check-ups indicated statistically significant differences in age, gender, region, education level, monthly income, employment status, obesity, smoking, alcohol consumption, exercise, and marital status. After adjustment for demographic, socioeconomic factors, and health-related behaviors, woman non-participants were more likely to have metabolic syndrome, pre-hypertension, hypertension, prediabetes, and diabetes, and man non-participants were more likely to have pre-diabetes and diabetes. CONCLUSION: Subjects who participated in periodic health check-ups had fewer CVD-related risk factors than non-participants. Thus, health care providers should encourage non-participants to attend periodic health check-ups so that appropriate interventions can be implemented and decrease the risk for CVDs in these individuals.

Comparison of Long Term Follow-up Chest CT Imaging in Adult and Pediatric Patients with Humidifier Disinfectant-related Lung Injury.

BACKGROUND: To compare the chest computed tomography (CT) images of children and adults in families with clusters of humidifier disinfectant-related lung injury (HDLI) after cessation of exposure to humidifier disinfectant (HD). METHODS: We reviewed medical records of 19 families with 43 patients (21 adults, 22 children) among families, which had at least one adult and one child with HDLI. Each family was exposed to the same HD exposure environment. RESULTS: In adults, centrilobular nodules were predominant (95.2%) in chronic HDLI findings after cessation of exposure to HD, however, in children, normal pattern was most prevalent on chest CT (45.5%), followed by centrilobular nodule (36.4%), bizarre lung cysts (36.4%), and reticulation (13.6%). CONCLUSION: Unlike the known chronic HDLI finding of adults, centrilobular nodules were only present in 36.4% of children. The frequency of bizarre lung cysts were significantly greater in children than that in adults after cessation of similar exposure to HD. Thus, bizarre lung cysts may be useful as another novel finding of chronic HDLI in children who have no history of pulmonary infection or other perinatal disorder such as hyaline membrane disease or other interstitial lung disease.

Characteristics of a new respiratory syndrome associated with the use of a humidifier disinfectant: humidifier disinfectant-related respiratory syndrome (HDRS).

OBJECTIVES: The purpose of this study was to characterize a new respiratory syndrome associated with exposure to a humidifier disinfectant (HD) in South Korea that is distinct from the well-known HD-related lung injury (HDLI). The authors identified this condition in 24 study subjects who were family members of patients with definite or probable HDLI (referred to as index cases), and were exposed to HD in the same room as the index cases. MATERIAL AND METHODS: The authors reviewed medical records of 236 family members in 110 families who were exposed to HD in the same rooms and residences as the index cases. RESULTS: They identified 24 family members who were exposed to HD in the same rooms and residences as the index cases, and who developed respiratory disorders that were distinct from HDLI. The clinical signs and symptoms of these individuals were in the upper respiratory tract, such as allergic rhinitis and croup, or in the lower respiratory tract, such as bronchitis and pneumonia. The diffusing capacity of the lung fordetermicarbon monoxide was reduced in 9 of 12 children (data not available for 1 child), and in 4 of 5 adults (data not available for 6 adults). The percent forced vital capacity and forced expiratory volume in one second/forced vital capacity ratios were within the normal ranges in most patients. The computed tomography findings, which mostly indicated non-specific inflammation, were inconsistent with the radiological diagnostic criteria for HDLI, but were abnormal in 8 of 11 adults, and in 2 of 13 children. CONCLUSIONS: The authors propose a new condition, i.e., HD-related respiratory syndrome (HDRS), which is characterized by mild to moderate or atypical respiratory symptoms and signs, and is related to HD exposure, but is distinct from HDLI. The recognition of HDRS may provide a basis for understanding the natural history of HD-related respiratory problems, and for capturing the whole spectrum of HD-related clinical manifestations in the respiratory tract. Int J Occup Med Environ Health. 2020;33(6):829-39.

Changes of Atmospheric and Blood Concentrations of Lead and Cadmium in the General Population of South Korea from 2008 to 2017.

We measured changes in atmospheric and blood levels of lead and cadmium in the South Korean general population during the past decade. Blood data of 16,873 adults were taken from the Korean National Health and Nutrition Examination Survey (KNHANES, 2008-2017). Atmospheric data were taken from 66 air quality monitoring sites in 16 different regions in South Korea. From 2008 to 2017, the geometric mean (GM) blood lead level decreased from 2.37 to 1.46 µg/dL (38.4% decrease), and the atmospheric lead concentration decreased by 61.0% in the overall population. During this time, the GM blood cadmium level decreased from 0.88 to 0.72 µg/L (18.2% decrease), and the atmospheric cadmium concentration decreased by 63.6%. Multiple linear regression analysis indicated that a half reduction in air lead was associated with a 0.09 µg/dL decrease in blood lead (95% CI: 0.03 to 0.15) in a subgroup of the metropolitan city population. However, a half reduction in air cadmium had no significant effect on blood cadmium. Multiple linear regression analyses indicated that the decrease in blood lead level over 10 years in Korea was related to the decrease in atmospheric lead concentration. However, the decrease in blood cadmium level during this time was not significantly associated with the decrease in atmospheric cadmium concentration. Our findings suggest that inhalation is a major source of lead exposure, but not of cadmium exposure. Ingestion of dietary cadmium presumably has a stronger impact on blood cadmium levels.

Exposure to prenatal secondhand smoke and early neurodevelopment: Mothers and Children's Environmental Health (MOCEH) study.

BACKGROUND: The association between exposure to secondhand smoke (SHS) during pregnancy and a child's neurodevelopment has not been established yet. We explored the association between prenatal exposure to SHS and neurodevelopment at 24 months of age considering genetic polymorphism and breastfeeding in 720 mothers and their offspring enrolled in the Korean multicenter birth cohort study (Mothers and Children Environmental Health, MOCEH). METHODS: We quantified urine cotinine concentrations in mothers once from 12th to 20th gestational weeks and excluded those whose urine cotinine levels exceeded 42.7 ng/ml to represent SHS exposure in early pregnancy. Mental developmental index (MDI) and psychomotor developmental index (PDI) values were measured using the Korean version of the Bayley Scales of Infant Development II (K-BSID-II) at 24 months of age. A general linear model was used to assess the relationship between maternal urinary cotinine level and neurodevelopment. RESULTS: MDI scores were inversely associated with cotinine [ß = - 2.73; 95% confidence interval (CI): - 5.32 to - 0.15] in children whose mothers had early pregnancy urinary cotinine levels >1.90 ng/ml. No association was evident in children whose mothers had cotinine levels ≤1.90 ng/ml. This negative association was more pronounced in children whose mothers had both Glutathione S-transferases mu 1 (GSTM1) and theta 1 (GSTT1) null type [ß = - 5.78; 95% CI: -10.69 to - 0.87], but not in children whose mothers had any present type of GSTM1/GSTT1 [ß = - 1.64; 95% CI: -4.79 to 1.52]. The association was no longer significant when children received breast milk exclusively for up to 6 months [ß = - 0.24; 95% CI: -4.69 to 4.20] compared to others [ß = - 3.75; 95% CI: -7.51 to 0.00]. No significant association was found for PDI. CONCLUSIONS: Maternal exposure to SHS during pregnancy may result in delayed MDI in early childhood. This effect might be modified by genetic polymorphism and breastfeeding behavior.

Association of Blood Pressure with Blood Lead and Cadmium Levels in Korean Adolescents: Analysis of Data from the 2010-2016 Korean National Health and Nutrition Examination Survey.

BACKGROUND: We evaluated the association of blood pressure (BP) with blood levels of cadmium, lead, and cadmium and lead together (cadmium + lead) in a representative sample of adolescents from Korea. METHODS: We used 2010-2016 data from the Korean National Health and Nutrition Examination Survey. This cross-sectional study enrolled adolescents aged at 10-18 years-old who completed a health examination survey and had blood measurements of lead and cadmium. The association of adjusted mean differences in diastolic and systolic BP with doubling of blood lead and cadmium were estimated by regression of BP against log2-transformed blood metals and their quartiles after covariate adjustment. Adjusted odds ratio for prehypertension were calculated for log2-transformed blood levels of lead and cadmium and their quartiles. RESULTS: Our analysis of adolescents in Korea indicated that blood levels of lead and cadmium were not significantly associated with increased BP or risk of prehypertension. However, the cadmium + lead level was associated with prehypertension. Previous studies showed that blood levels of lead and cadmium were associated with increased BP and risk of hypertension in adult populations. We found no such association in Korean adolescents. CONCLUSION: We found that the cadmium + lead level was associated with prehypertension. The differences between adults and adolescents are because adolescents generally have lower levels of these blood metals or because adolescents only rarely have hypertension.

Correction to: Guidelines for recognition of occupational cancers in Korea: the results of scientific review by Korean Society of Occupational and Environmental Medicine (2013-2016).

[This corrects the article DOI: 10.1186/s40557-018-0223-2.].

Perinatal factors and the development of childhood asthma.

BACKGROUND: Perinatal factors are suspected to have a significant impact on the development of asthma; however, sufficiently powered studies have not been performed to investigate this issue. OBJECTIVE: To evaluate whether perinatal factors and other risk factors have an independent or combined effect on the development of asthma. METHODS: This study involved 3,770 children (mean age 9.1 years, range 5.68-12.16 years; 51.9% boys) who were enrolled in the Elementary School Student Cohort (2009-2014) in Ulsan University Hospital (Ulsan, Korea). Subjects were divided into an asthma group (n = 514) and a non-asthma group (n = 3,256). RESULTS: Multivariate analyses showed that early life (within first week) oxygen therapy (adjusted odds ratio [aOR] 1.864, 95% confidence interval [CI] 1.156-3.004) and breastfeeding (aOR 0.763, 95% CI 0.606-0.960) were 2 significant perinatal factors influencing the development of asthma. Environmental tobacco smoke (aOR 1.634, 95% CI 1.298-2.058) and parental allergic disease (aOR 1.882, 95% CI 1.521-2.328) also were identified as risk factors. Using subgroup analyses, combined effects on asthma development were observed between perinatal factors (early life oxygen therapy and breastfeeding) and other risk factors (vicinity to major roadway [traffic-related air pollution], environmental tobacco smoke, parental allergic disease, and atopy). CONCLUSION: Early life oxygen therapy and breastfeeding were identified as 2 important perinatal factors influencing the development of asthma. Furthermore, these factors showed combined effects with other risk factors (environmental tobacco smoke, traffic-related air pollution, parental allergic disease, and atopy) on the development of asthma.

Guidelines for recognition of occupational cancers in Korea: the results of scientific review by Korean Society of Occupational and Environmental Medicine (2013-2016).

This thematic collection includes the articles to review eleven occupational cancer related risks or working conditions and to propose the guidelines of S. Korea.

Review of carcinogenicity of hexavalent chrome and proposal of revising approval standards for an occupational cancers in Korea.

BACKGROUND: The objective of this study is to suggest revised recognition standards for occupational disease due to chromium (VI) by reflecting recent domestic and international research works and considering domestic exposure status with respect to target organs, exposure period, and cumulative exposure dose in relation to the chromium (VI)-induced occupational disease compensation. METHODS: In this study, the reports published by major international institutions such as World Health Organization (WHO) International Agency for Research on Cancer (IARC) (2012), Occupational Safety and Health Administration (OSHA) (2006), National Institute for Occupational Safety and Health (NIOSH) (2013), American Conference of Governmental Industrial Hygienists (ACGIH) (2004), National Toxicology Program (NTP) (2014), and Agency for Toxic Substances and Disease Registry (ASTDR) (2012) were reviewed and the recent research works searched by PubMed were summarized. RESULTS: Considering the recent research works and the domestic situation, only lung cancer is conserved in the legislative bill in relation to chromium (VI), and the exposure period is not included in the bill. Nasal and paranasal sinus cancer was excluded from the list of cancers that are compensated as the chromium (VI)- induced occupational disease, while lung cancer remains in the list. In the view of legislative unity, considering the fact that only the cancers having sufficient evidence are included in the conventional list of cancers compensated as occupational disease, nasal and paranasal sinus cancer having limited evidence were excluded from the list.The exposure period was also removed from the legislative bill due to the insufficient evidence. Recent advices in connection with cumulative exposure dose were proposed, and other considerable points were provided with respect to individual occupational relevance. CONCLUSIONS: It is suggested that the current recognition standard which is "Lung cancer or nasal and paranasal sinus cancer caused by exposure to chromium (VI) or compounds thereof (exposure for two years or longer), or nickel compounds" should be changed to "Lung cancer caused by exposure to chromium (VI) or compounds thereof, and lung cancer or nasal and paranasal sinus cancer caused by exposure to nickel compounds".

Environmental and Body Concentrations of Heavy Metals at Sites Near and Distant from Industrial Complexes in Ulsan, Korea.

BACKGROUND: Industrial pollution may affect the heavy metal body burden of people living near industrial complexes. We determined the average concentrations of atmospheric heavy metals in areas close to and distant from industrial complexes in Korea, and the body concentrations of these heavy metals in residents living near and distant from these facilities. METHODS: The atmospheric data of heavy metals (lead and cadmium) were from the Regional Air Monitoring Network in Ulsan. We recruited 1,148 participants, 872 who lived near an industrial complex ("exposed" group) and 276 who lived distant from industrial complexes ("non-exposed" group), and measured their concentrations of blood lead, urinary cadmium, and urinary total mercury. RESULTS: The results showed that atmospheric and human concentrations of heavy metals were higher in areas near industrial complexes. In addition, residents living near industrial complexes had higher individual and combined concentrations (cadmium + lead + mercury) of heavy metals. CONCLUSION: We conclude that residents living near industrial complexes are exposed to high concentrations of heavy metals, and should be carefully monitored.

Health effects of environmental pollution in population living near industrial complex areas in Korea.

Several epidemiological studies have reported an association between environmental pollution and various health conditions in individuals residing in industrial complexes. To evaluate the effects of pollution from industrial complex on human health, we performed a pooled analysis of environmental epidemiologic monitoring data for residents living near national industrial complexes in Korea. The respiratory and allergic symptoms and the prevalence of acute and chronic diseases, including cancer, were used as the outcome variables for health effects. Multiple logistic regression analysis was used to analyze the relationship between exposure to pollution from industrial complexes and health conditions. After adjusting for age, sex, smoking status, occupational exposure, level of education, and body mass index, the residents near the industrial complexes were found to have more respiratory symptoms, such as cough (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.06 to 1.31) and sputum production (OR, 1.13; 95% CI, 1.03 to 1.24), and symptoms of atopic dermatitis (OR, 1.10; 95% CI, 1.01 to 1.20). Among residents of the industrial complexes, the prevalence of acute eye disorders was approximately 40% higher (OR, 1.39; 95% CI, 1.04 to 1.84) and the prevalence of lung and uterine cancer was 3.45 times and 1.88 times higher, respectively, than those among residents of the control area. This study showed that residents living in the vicinity of industrial complexes have a high risk of acute and chronic diseases including respiratory and allergic conditions. These results can be used as basic objective data for developing health management measures for individuals residing near industrial complexes.

µSex, pregnancy, and age-specific differences of blood manganese levels in relation to iron status; what does it mean?

The objective of the present study was to evaluate sex, menopause, pregnancy, and age-specific differences of blood manganese (Mn) levels in relation to iron status, and to assess the toxicological implications of these relationships. Females of childbearing age have higher concentrations of blood Mn than males because women have lower concentrations of ferritin. Previous studies indicated significant increases in blood Mn levels throughout pregnancy, and that the geometric mean of blood Mn was significantly higher in premenopausal women than postmenopausal women. This may be due to the enhanced absorption of Mn because of upregulation of iron absorption, which is especially important during late pregnancy. Mn concentrations are highest in infancy, decreased with age up to adolescence, and did not change during adulthood. Thus, the relationship of iron with Mn may be the major factor affecting blood Mn levels according to menstrual stage, reproductive status, menopausal factors, and age. However, Mn absorbed via the gastrointestinal system seems to be less neurotoxic than inhaled or parenteral Mn, due to the tight enterohepatic homeostatic control of this essential element. Furthermore, children and pregnant women had no adverse health effects from blood levels of Mn that were associated with adverse effects in adult workers. In conclusion, the differences between a physiological and a pathological hypermanganesemia complicate interpretation of the dose-response relationship.

Modeling the effects of pollutant emissions from large industrial complexes on benzene, toluene, and xylene concentrations in urban areas.

This study utilized the Community Multiscale Air Quality model to simulate the spatial distribution of benzene, toluene, and xylene (BTX) concentrations from large national industrial complexes (IC) located in the Ulsan metropolitan region (UMR). Through controlling pollutant emissions from major IC, this study performed a quantitative analysis of the influence of pollutant emissions on BTX concentrations in surrounding urban areas. The results showed that approximately 40% of the annual average BTX concentrations in nearby urban grids were directly influenced by pollutant emissions from the IC. Seasonal modeling results indicated that average BTX concentrations were high around petrochemical complexes, with higher concentrations in the surrounding urban areas during the summer (July). All three of the BTX pollutants showed similar seasonal differences. Daily contributions differed significantly throughout the modeling period, with some values reaching a maximum of 80% during July. Overall, when urban areas were located downwind of the IC, contributions rose. Moreover, this study compared the differences in BTX contributions at each measurement point within the IC and urban areas, which showed that the influence of the IC emissions decreased significantly with distance. The spatial distribution and direct influence of the IC on BTX concentrations in the UMR identified through this study could be used to provide input data in environmental epidemiological studies.

The association between cadmium and lead exposure and blood pressure among workers of a smelting industry: a cross-sectional study.

BACKGROUND: Lead and cadmium are harmful heavy metals that are used for a variety of occupational purposes. Considering their potentially hazardous effects on health, studies on the association between exposure to these two heavy metals and health disorders have been actively conducted. This study aimed to determine the association between blood lead and cadmium levels and blood pressure in workers exposed to lead and cadmium in a smelter. METHODS: Nine hundred and sixty-three male workers who worked in a smelter, and underwent medical examinations at the Ulsan University Hospital between January 1 and December 31, 2014, were selected as participants. Among them, 310 subjects whose data on height, weight, blood pressure, fasting blood glucose, lipid profile, and blood lead and cadmium levels were available and who answered the questionnaire were selected as the final participants. We investigated the drinking habit, smoking status, exercise adequacy, and family history of hypertension of these workers using formal questionnaires. A statistical analysis was conducted using Student's t-test, analysis of variance, and linear or logistic regression. RESULTS: The association between blood lead and cadmium levels and blood pressure was analyzed through statistical adjustment of the risk factors of hypertension. Results showed an association between blood cadmium level and blood pressure elevation. However, blood lead level was found to be not correlated with blood pressure elevation. CONCLUSIONS: This study shows the association between blood cadmium level and systolic blood pressure (SBP) and diastolic blood pressure (DBP) elevation. TRIAL REGISTRATION: IRB No. 2017-03-037. Retrospectively Registered 30 March 2017.

Neurodevelopment for the first three years following prenatal mobile phone use, radio frequency radiation and lead exposure.

BACKGROUND: Studies examining prenatal exposure to mobile phone use and its effect on child neurodevelopment show different results, according to child's developmental stages. OBJECTIVES: To examine neurodevelopment in children up to 36 months of age, following prenatal mobile phone use and radiofrequency radiation (RFR) exposure, in relation to prenatal lead exposure. METHODS: We analyzed 1198 mother-child pairs from a prospective cohort study (the Mothers and Children's Environmental Health Study). Questionnaires were provided to pregnant women at ≤20 weeks of gestation to assess mobile phone call frequency and duration. A personal exposure meter (PEM) was used to measure RFR exposure for 24h in 210 pregnant women. Maternal blood lead level (BLL) was measured during pregnancy. Child neurodevelopment was assessed using the Korean version of the Bayley Scales of Infant Development-Revised at 6, 12, 24, and 36 months of age. Logistic regression analysis applied to groups classified by trajectory analysis showing neurodevelopmental patterns over time. RESULTS: The psychomotor development index (PDI) and the mental development index (MDI) at 6, 12, 24, and 36 months of age were not significantly associated with maternal mobile phone use during pregnancy. However, among children exposed to high maternal BLL in utero, there was a significantly increased risk of having a low PDI up to 36 months of age, in relation to an increasing average calling time (p-trend=0.008). There was also a risk of having decreasing MDI up to 36 months of age, in relation to an increasing average calling time or frequency during pregnancy (p-trend=0.05 and 0.007 for time and frequency, respectively). There was no significant association between child neurodevelopment and prenatal RFR exposure measured by PEM in all subjects or in groups stratified by maternal BLL during pregnancy. CONCLUSIONS: We found no association between prenatal exposure to RFR and child neurodevelopment during the first three years of life; however, a potential combined effect of prenatal exposure to lead and mobile phone use was suggested.