Current Situation and Causes Analysis of Cadmium Pollution in the Kakehashi River Basin.

Cadmium (Cd) pollution is a public environmental problem worthy of attention. Long-term exposure to Cd may have adverse effects on human health. Our previous study showed that urinary concentration of Cd (U-Cd) in the residents decreased when Cd-polluted paddy soil was removed. However, from 2008 to 2014, the concentration of U-Cd increased. At the same time, the concentration of urinary ß2-microglobulin (ß2-MG), which is considered to be an early sign of cadmium-induced renal dysfunction, increased continuously. To find the cause of elevated urinary cadmium (U-Cd) in residents of cadmium-contaminated areas, we measured the concentration of cadmium in the blood (B-Cd) of 29 elderly residents (15 female and 14 male) and edible rice (R-Cd), and correlations between R-Cd, B-Cd, and U-Cd were analyzed in the formerly cadmium-polluted areas (the Kakehashi River basin). In 2016, we collected blood, urine, and rice samples from each participant. The analysis showed a significant correlation between age and B-Cd, U-Cd, and ß2-MG. However, there was no significant correlation between R-Cd and U-Cd, B-Cd, or ß2-MG concentrations. Although we found a slightly higher level of Cd in rice and urine than reported in 2008, we cannot be sure that it indicates an increased Cd contamination in the Kakehashi River basin because larger studies are required for such a conclusion. The increased urinary Cd concentrations in this area may be because Cd in tissues and organs returns to blood and urine as participants age, which leads to an increasing trend.

Prenatal Exposure to Heavy Metals and Adverse Birth Outcomes: Evidence From an E-Waste Area in China.

Electronic waste that has not been properly treated can lead to environmental contamination including of heavy metals, which can pose risks to human health. Infants, a sensitive group, are highly susceptible to heavy metals exposure. The aim of this study was to investigate the association between prenatal heavy metal exposure and infant birth outcomes in an e-waste recycling area in China. We analyzed cadmium (Cd), chromium (Cr), manganese (Mn), lead (Pb), copper (Cu), and arsenic (As) concentrations in 102 human milk samples collected 4 weeks after delivery. The results showed that 34.3% of participants for Cr, which exceeds the World Health Organization (WHO) guidelines, as well as the mean exposure of Cr exceeded the WHO guidelines. We collected data on the birth weight (BW) and length of infants and analyzed the association between metal concentration in human milk and birth outcomes using multivariable linear regression. We observed a significant negative association between the Cd concentration in maternal milk and BW in female infants (ß = -162.72, 95% CI = -303.16, -22.25). In contrast, heavy metals did not associate with birth outcomes in male infants. In this study, we found that 34.3% of participants in an e-waste recycling area had a Cr concentration that exceeded WHO guidelines, and there was a significant negative association between prenatal exposure to the Cd and infant BW in females. These results suggest that prenatal exposure to heavy metals in e-waste recycling areas may lead to adverse birth outcomes, especially for female infants.

Cadmium body burden and health effects after restoration of cadmium-polluted soils in cadmium-polluted areas in the Jinzu River basin.

BACKGROUND: Itai-itai disease is caused by environmental cadmium (Cd) pollution in the Jinzu River basin in Japan. To reduce the Cd contamination of rice, soil restoration of paddy fields was carried out. We evaluated the effect of soil restoration on the health status of residents of the former Cd-polluted area. METHODS: Participants were 1,030 men and 944 women who lived in the area of restoration of Cd-polluted rice paddies. First morning urine was collected and urinary Cd, ß2-microglobulin (ß2MG), and N-acetyl-ß-D-glucosaminidase (NAG) levels were measured. Associations among age, years of residence before and after soil restoration, and urinary Cd, ß2MG, and NAG levels were evaluated by multiple regression analysis. RESULTS: The geometric mean (interquartile range) of urinary Cd (µg/g Cr) was 1.00 (0.58-1.68) in men and 1.67 (1.02-2.91) in women. The geometric means of urinary ß2MG (µg/g Cr) and NAG (U/g Cr) were 174.6 (92.6-234.2) and 1.47 (0.72-3.14) in men, and 217.6 (115.3-28.7) and 1.48 (0.73-2.96) in women, respectively. Urinary Cd, ß2MG, and NAG were significantly positively correlated (p < 0.01 all). Age and duration of residence in the Cd-polluted area before soil restoration were independently associated with urinary Cd, ß2MG, and NAG. Among the 916 participants who had resided in the area before the soil restoration, urinary Cd concentrations were significantly higher, thus by 1.03-fold (95% CI, 1.01-1.04) in men and 1.03-fold (95% CI, 1.01-1.05) in women, when the years of residence before soil restoration by each 5-years increment. By contrast, urinary Cd concentrations were significantly lower, thus 0.97-fold (95% CI, 0.96-0.99) lower in men and 0.97-fold (95% CI, 0.95-0.99) lower in women, by each 5-year increment of residence after soil restoration. A similar association was observed for urinary ß2MG concentration, and no significant association was observed for urinary NAG levels in men or women. CONCLUSIONS: Cd exposure and associated renal tubular dysfunction in residents of a former Cd-polluted area were influenced by Cd exposure from the environment prior to soil restoration. Soil restoration in Cd-polluted areas reduced the Cd exposure of local residents.

Effect of renal tubular damage on non-cancer mortality in the general Japanese population living in cadmium non-polluted areas.

This study aimed to clarify the cause-effect relationship between renal tubular damage and non-cancer mortality in the general Japanese population. We conducted a 19-year cohort study including 1110 men and 1,03 women who lived in three cadmium-non-polluted areas in 1993 or 1994. Mortality risk ratios based on urinary ß2-microglobulin (ß2MG) and N-acetyl-ß-glucosaminidase (NAG) concentrations were estimated for specific non-cancer diseases using the Fine and Gray competing risks regression model. In men, continuous urinary NAG (+1 µg/g cre) concentrations were significantly correlated with increased mortality caused by diseases of the respiratory system (hazard ratio (HR): 1.09, 95% confidence interval (CI): 1.03-1.15). Urinary ß2MG (+100 µg/g cre) concentrations were significantly correlated with increased mortalities caused by kidney and urinary tract diseases (HR: 1.01, 95% CI: 1.00-1.03), renal diseases (HR: 1.01, 95% CI: 1.00-1.03), renal failure (HR: 1.02, 95% CI: 1.00-1.03), and external causes of mortality (HR: 1.01, 95% CI: 1.00-1.02). In women, urinary NAG (+1 µg/g cre) concentrations were significantly associated with increased mortality caused by ischemic heart diseases (HR: 1.02, 95% CI: 1.00-1.04) and kidney and urinary tract diseases (HR: 1.01, 95% CI: 1.00-1.04). Urinary ß2MG (+100 µg/g cre) concentrations were significantly correlated with increased mortality caused by cardiovascular diseases (HR: 1.01, 95%CI: 1.00-1.02), ischemic heart diseases (HR: 1.01, 95%CI: 1.00-1.02), and kidney and urinary tract diseases (HR: 1.02, 95% CI: 1.01-1.03). The present study indicates that renal tubular damage was significantly related to several non-cancer disease causes of mortality in Japan's general population living in cadmium-non-polluted areas.

Multiple exposures to heavy metals and changes in steroid hormones production in 4-year-old children.

BACKGROUND: Prenatal exposure to multiple heavy metals can interfere with early neurodevelopment, lead to changes in sex hormone concentrations in children, and affect female reproductive health. To date, the influence of prenatal exposure to heavy metals on the endocrine system of children in Chinese electronic waste (e-waste) recycling areas has not been elucidated. METHODS: Four weeks after delivery, 10 mL of human milk was collected for analysis of three heavy metals (lead (Pb), cadmium (Cd), and mercury (Hg)) via inductively coupled plasma mass spectrometry (ICP-MS). Four serum steroid hormones, including progesterone, testosterone, androstenedione (A-dione), and dehydroepiandrosterone (DHEA), were analyzed in 4-year-old children (25 boys and 17 girls). A multiple linear regression (MLR) model was implemented to investigate the association between each individual metal and serum steroid hormone. The exposure-response relationships were explored by generalized additive models (GAMs). Additionally, a Bayesian kernel machine regression (BKMR) model was used to assess the effects of multiple heavy metal exposures on each steroid hormone. RESULTS: The MLR results show a significant positive association between a natural log unit increase in Hg and DHEA levels after adjusting for confounders (ß = 65.50, 95% confidence interval (CI) = 4.37, 126.62). According to the GAM, the univariate exposure-response relationship of Hg on DHEA was almost linear. However, this association was attenuated based on the multiple metal MLR and BKMR results after accounting for multiple heavy metal exposures. SIGNIFICANCE: Prenatal Hg exposure may affect sex hormones in children by affecting DHEA levels. IMPACT STATEMENT: Prenatal maternal exposure to Hg may have long-term effects on the next generation. Hence, regulatory measures to reduce Hg exposure and long-term monitoring of children's health in e-waste areas are needed.

A 30-year follow-up study in a former cadmium-polluted area of Japan: the relationship between cadmium exposure and ß2-microglobulin in the urine of Japanese people.

Cadmium (Cd) is an environmental pollutant. Long-term exposure to Cd may lead to adverse health effects in humans. Our epidemiological studies showed that urinary Cd (U-Cd) concentrations increased from 2008 through 2014, although they decreased from 1986 through 2008. The aim of this study was to elucidate the long-term effects of the changing trend of cadmium exposure levels (U-Cd) on residents' renal function within 30 years after Cd exposure ceased. In 2016, urine samples were collected from each subject by visiting 20 elderly Japanese people (9 females and 11 males) living in the Kakehashi River basin, a previously Cd-polluted area in Ishikawa, Japan. The geometric means of the ß2-microglobulin (ß2-MG) and urinary Cd (U-Cd) continued to increase from 2014 until 2016. Furthermore, Cd concentration and ß2-MG in urine were still higher than those in the non-polluted areas in Japan. Multivariate linear regression was performed to associate ß2-MG (dependent variable) and U-Cd with sex and age (independent variables). Significant correlations were found among age, U-Cd, and ß2-MG, and these were clearer in females than in males. In summary, we propose that three decades after Cd exposure ceased, age is associated with ß2-MG more strongly than Cd for bodily impact. Moreover, renal tubular dysfunction is irreversible and worsens after exposure to Cd, with females being more sensitive to exposure.

Evaluating postnatal exposure to six heavy metals in a Chinese e-waste recycling area.

This study is the first to assess postnatal exposure to heavy metals using breast milk in an electronic waste (e-waste) recycling area. From January to April 2021, 102 and 97 breastfeeding women were recruited from an e-waste recycling area and a control area, respectively. Four weeks after delivery, medical staff collected 20 mL of breast milk from each participant. The breast milk was tested for six heavy metals (lead, cadmium, chromium, arsenic, copper, and manganese) using inductively coupled plasma mass spectrometry (ICP-MS). The estimated daily intake (EDI) of infants during breastfeeding was calculated to assess the impact of postnatal exposure to heavy metals on infant health. The concentrations of chromium and lead in the breast milk were significantly higher in the e-waste recycling area than in the control area. Chromium concentrations in breast milk was 34.3%, exceeding the permissible limits set by the World Health Organization (WHO), in the e-waste recycling area, which is 16 times higher than that in the control areas. The EDIs of lead and chromium in the e-waste area were twice as those in the control area. This strongly indicates that the potential impact of postnatal exposure to lead and chromium on infant and child health in e-waste recycling areas cannot be ignored. Infants and children in e-waste recycling areas are at risk of long-term exposure to heavy metals. Therefore, ongoing health monitoring is necessary.

The Relationship of Dioxin Levels in Serum of 9-Year-Old Vietnamese Children and Their Mothers' Breast Milk.

In this study, we measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in the blood of 9-year-old children living in a dioxin hotspot area and a nonexposed area in Vietnam. Forty-five blood samples were collected in the hotspot area while twelve pooled blood samples were collected in the nonexposed area. We found that the dioxin level of children in the hotspot was significantly higher than that of children in the nonexposed area. The total TEQ of PCDD/Fs in the hotspot and the nonexposed was 10.7 and 3.3 pg TEQ/g fat, respectively. However, TCDD, the maker of Agent Orange, was not detected in the blood of children in the hotspot area. In the hotspot area, four congeners 1,2,3,4,6,7,8-HpCDD, 1,2,3,4,7,8-HxCDF, 1,2,3,6,7,8-HxCDF, and 1,2,3,4,6,7,8-HpCDF in mothers' breast milk showed a significantly positive correlation with those in children's serum although the correlations of 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF were not significant. In addition, the duration of breastfeeding also correlates with dioxins in children. These results suggested that children in the hotspot area were exposed to dioxin through mothers' milk and other foods or environmental factors. The present study is the first study that shows dioxin levels in Vietnamese children.

Relationship between dioxins and steroid hormone in 6-year-olds: A follow-up study in an e-waste region of China.

We conducted a follow-up observational study on the effects of dioxin exposure on the synthesis of steroid hormones in infants during the perinatal period. The participants included 42 pairs of mothers and infants that were previously studied in 2015. We analyzed four types of steroid hormones including progesterone, testosterone, androstenedione (A-dione), and dehydroepiandrosterone (DHEA) in the serum samples of 6-year-olds and the concentration of dioxins in breast milk. A multivariate linear regression was performed to associate steroid hormones (dependent variables) and dioxins with the body mass index (BMI), sex, age, and residence of participants (independent variables). The results were reported as ß (standardized coefficient) and p-values. We found that dioxins have a significant negative correlation with DHEA and A-dione but no significant relationship with progesterone and testosterone. However, in previous studies, we found that testosterone and progesterone levels were significantly related to dioxins in 4-year-olds. We concluded that dioxins can affect the level of steroid hormones, but their effects fluctuate, and the harm caused by dioxins in children requires further long-term monitoring.

Renal tubular dysfunction and cancer mortality in the Japanese general population living in cadmium-non-contaminated areas.

The relationship between cadmium exposure, exposure-related renal tubular dysfunction, and mortality have been reported, mainly in the residents of Cd-contaminated areas in Japan. The aim of this study was to establish the cause-effect relationship between renal tubular dysfunction and cancer mortality in the general population in non-contaminated areas. A 19-year cohort study was conducted in 1110 men and 1703 women in 1993 or 1994, who lived in three cadmium-non-contaminated areas. Mortality risk ratios of urinary ß2-microglobulin (ß2MG) and N-acetyl-ß-glucosaminidase (NAG) for all malignant neoplasms and specific cancers were estimated using the Fine and Gray competing risks regression model. Significant hazard ratios (HRs) for liver and pancreas cancer were observed for NAG (liver: HR corresponding to an increase of 1 IU/g cr, 1.10, 95%CI, 1.02-1.19, pancreas: HR, 1.10, 95%CI, 1.02-1.19) in men. In women, a negative HR was observed for NAG (lung cancer: HR 0.80, 95% CI, 0.67-0.96) and for ß2MG (all malignant neoplasms: HR, 0.97, 95% CI, 0.93-1.00). The present study indicated that renal tubular dysfunction was significantly related to mortality in the general population of cadmium-non-contaminated areas in Japan.

The Relationship between the Urinary Cadmium Concentration and Cause-Specific Mortality in Subjects without Severe Renal Damage: A 35-Year Follow-Up Study in a Cadmium-Polluted Area of Japan.

We evaluated the association between urinary cadmium concentration (uCd, µg/g Cr) and risk of cause-specific mortality according to urinary ß2-microglobulin (MG) concentration. Participants were 1383 male and 1700 female inhabitants of the Cd-polluted Kakehashi River basin. The uCd and ß2-MG were evaluated in a survey in 1981-1982, where those participants were followed-up over 35 years later. Among the participants with a urinary ß2-MG < 1000, the hazard ratios (HRs) (95% confidence interval) for mortality were significantly higher in those with a uCd of ≥10.0 compared with <5.0 for cardiovascular disease [HR 1.92 (1.08-3.40) for men, 1.71 (1.07-2.71) for women], pneumonia or influenza [2.10 (1.10-4.00) for men, 2.22 (1.17-4.19) for women], and digestive diseases [for men; 3.81 (1.49-9.74)]. The uCd was significantly associated with mortality from heart failure in women and digestive diseases in men, after adjustment for other causes of death using the Fine and Gray competing risk regression model. For participants with a urinary ß2-MG of ≥1000, no significant association was observed between uCd and any major cause of death. In the absence of kidney damage, Cd may increase the risk of death from cardiovascular disease, pneumonia, and digestive diseases.

Decreased serum testosterone levels associated with 17ß-hydroxysteroid dehydrogenase activity in 7-year-old children from a dioxin-exposed area of Vietnam.

Since 2008, we have conducted epidemiological cohort studies on the relationship between dioxin exposure and disruption with children in the area sprayed with defoliants during the Vietnam War. In a long-term survey of children through the age of five, we observed androgen disruption due to decreased dehydroepiandrosterone (DHEA) and testosterone levels. In this study of 7-year-old, we separately elucidated androgen disruption for boys and girls, and discussed with respect to hormone disruption with sex differences on the steroid hormone biosynthesis process. This follow-up was conducted with 96 mother-child pairs in Vietnam (hotspot area: 45, non-sprayed area: 51). We took a questionnaire, the physical measurement and assayed 7 steroid hormones in their serum by LC-MS/MS. We examined the relationship between the hormone levels in the serum and dioxin levels in the maternal breast milk. The results showed that the serum DHEA level in the 7-year-old children in the hotspot recovered to levels in the non-sprayed area. The testosterone level of 66.5 pg/mL for boys in the non-sprayed area was 1.5 times the girls level of 44.6 pg/mL, a male-dominant effect. The testosterone level in boys and girls from the hotspot were significantly lower than in the non-sprayed area with no sex difference. The 17ß-hydroxysteroid dehydrogenase (17ß-HSD) activity was significantly higher in boys than in the girls from the non-sprayed area, but was significantly lower in the hotspot boys than in the non-sprayed area boys. Both the testosterone level and 17ß-HSD activity in the boys were inversely correlated with the TEQ total PCDD/Fs in the maternal breast milk. These results indicated that dioxin delayed the expression of the testosterone level and 17ß-HSD activity with growth in the 7-year-old boys. The serum DHEA in the 7-year-old children recovered to the levels of the children in the non-sprayed area.

The Association between Anthropometric Indices of Obesity and Chronic Kidney Disease in Middle-aged Japanese Men and Women: A Cohort Study.

Objective This study investigated associations between three indices of obesity-the body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR)-and the incidence of chronic kidney disease (CKD). Methods The employees of a company in Japan (1,725 men, 1,186 women; aged 35-55 years) had BMI, WC, and WHtR measured in health examinations. The incidence of CKD was determined at annual medical examinations over a six-year period. The hazard ratios for CKD were calculated using proportional hazard models, and the χ2 statistic was used to compare the strengths of the associations. Results The mean BMI (kg/m2), WC (cm), and WHtR were 23.6, 84.3, and 0.49 for men and 22.3, 79.7, and 0.50 for women, respectively. The incidence of CKD (/1,000 person-years) was 18.1 for men and 8.4 for women. In men, positive linear associations were observed between the BMI, WC, and WHtR and the risk of CKD, even after adjusting for the presence of metabolic abnormalities (p for trend <0.001, 0.012, and 0.023, respectively). In women, a linear association was observed only between the WHtR and CKD, not the BMI or WC (p for trend =0.042, 0.057, and 0.186). The χ2 statistics were the highest for the BMI in both men and women. Conclusion The BMI, WC, and WHtR were linearly associated with the risk of CKD independently of metabolic abnormalities in men, while the associations were weaker or not significant in women. The BMI was the most strongly associated with the incidence of CKD in both men and women.

The relationship between cadmium exposure and renal volume in inhabitants of a cadmium-polluted area of Japan.

This follow-up study was conducted over 30 years in a cadmium-polluted area of Japan. Urinary cadmium (U-Cd) concentration decreased by nearly half from 1986 to 2008 in men and women. However, it increased from 2008 to 2014 and maintained similar levels in 2016. Because renal atrophy may induce an increase in U-Cd, kidney volumes were determined using magnetic resonance imaging (MRI) scans in 2018. Based on the MRI results, we divided the participants into two groups, namely the normal group (n = 6, three men and three women) and the lesion group (n = 6, three men and three women). The level of urinary N-acetyl-ß-d-glucosaminidase/creatinine (U-NAG/Cr) in the lesion group was significantly higher than in the normal group. The level of serum alkaline phosphatase (Al-P) was positively associated with U-Cd. Age and renal cortex volumes showed significantly negative associations. However, U-Cd and renal cortex and kidney volumes showed no significant associations. These results suggest that U-NAG and serum Al-P were sensitive biomarkers to reflect renal tubular dysfunction and bone damage caused by cadmium poisoning. Individuals chronically exposed to Cd should be observed carefully, due to the increased effect of aging on renal cortex volumes.

Environmental cadmium exposure and noncancer mortality in a general Japanese population in cadmium nonpolluted regions.

The objective of this study was to assess the effect of environmental cadmium exposure according to urinary cadmium concentration (U-Cd) on noncancer mortality in a general Japanese population. We conducted a longitudinal study for 19 years in 2804 inhabitants (1107 men and 1697 women) in some cadmium nonpolluted regions in Japan. The participants were classified into quartiles based on U-Cd (µg/g cre) adjusted for urinary creatinine. Hazard ratio (HR) and 95% confidence interval (95% CI) for continuous U-Cd or the quartiles of U-Cd were calculated for noncancer mortality. By applying a Fine and Gray competing risk model, continuous U-Cd (+1 µg/g cre) showed significant HR for cardiocerebrovascular diseases (HR 1.05, 95% CI: 1.00-1.11), cerebrovascular diseases (HR 1.08, 95% CI: 1.01-1.16), and cerebral infarction (HR 1.11, 95% CI: 1.04-1.20) in men. However, notable significant HR for continuous and quartered U-Cd were not observed in women. In this study, U-Cd was associated with increased cardiocerebrovascular mortality in a general Japanese population, suggesting that environmental cadmium exposure is detrimental to the life prognosis in cadmium nonpolluted regions in Japan.

Relationship between urinary ß2 -microglobulin concentration and mortality in a cadmium-polluted area in Japan: A 35-year follow-up study.

The relationship between urinary ß2 -microglobulin (ß2 -MG) and the risk of all-cause mortality and cause-specific mortality in a cadmium (Cd)-polluted area was investigated in 3139 inhabitants (1404 men and 1735 women) of the Kakehashi River basin in Japan at 35-year follow-up. The subjects had been participants in the 1981-1982 health impact survey that assessed Cd-induced renal dysfunction, as measured by the urinary ß2 -MG concentration. Hazard ratios were calculated to assess the risk of all-cause and cause-specific mortality according to the urinary ß2 -MG concentrations. Risk ratios (RRs) were assessed using the Fine and Gray regression model to account for competing risks of cause-specific mortality. The mortality rate was significantly higher in participants with urinary ß2 -MG concentrations >1000 µg/g creatinine (Cr) for men and >300 µg/g Cr for women. In the proportional hazard model, higher urinary ß2 -MG concentrations were associated with higher risks of circulatory disease, digestive system diseases, and kidney and urinary tract diseases in men and women, and with senility for women. However, when competing risk was accounted for, the RRs were significantly higher only for kidney and urinary tract diseases in men and women (RR for each increment of 1000 µg/g Cr [95% confidence interval]: 1.02 [1.00-1.04] for men, and 1.01 [1.00-1.02] for women). The long-term prognosis of participants with renal tubular dysfunction was poor, most likely due to kidney and renal tract diseases.

Frequency of consumption of balanced meals, bodyweight gain and incident risk of glucose intolerance in Japanese men and women: A cohort study.

AIMS/INTRODUCTION: This cohort study assessed the risk for bodyweight gain and development of glucose intolerance based on the frequency of consumption of balanced meals including grain, fish or meat and vegetables. MATERIALS AND METHODS: The participants (8,573 men, 3,327 women) were employees of a company in Japan. A self-administered questionnaire was used to evaluate the frequency of balanced meal consumption. Bodyweight changes and the incidence of glucose intolerance (glycated hemoglobin >6.0%) during the 3-year follow-up period were determined through annual health examinations. RESULTS: The mean bodyweight change over a period of 3 years was 0.78 kg for men and 0.84 kg for women. A lower frequency of balanced meals was associated with a higher bodyweight gain for men (P for trend = 0.004), but not for women. During the study, 464 men and 115 women developed glucose intolerance. Overall, the frequency of balanced meals was not associated with the risk of glucose intolerance in either sex. However, the interaction between the frequency of balanced meals and degree of obesity had a significant effect on the incidence of glucose intolerance in men (P = 0.005), with less frequent consumption of balanced meals being associated with a higher risk for glucose intolerance among men with a BMI ≥25.0 kg/m2 (P for trend = 0.007). CONCLUSIONS: A higher frequency of balanced meals, including grain, fish or meat and vegetable dishes - important components of healthy Japanese food - was associated with a lower risk of glucose intolerance in obese men, but not in non-obese men and women.

Dioxins in breast milk of Chinese mothers: A survey 40 years after the e-waste recycling activities.

In the past two decades, numerous studies on dioxin concentrations in breast milk have been conducted in China. However, information concerning dioxin concentrations in breast milk from women living in e-waste recycling sites remains limited. Thus, this study aimed to evaluate health risk owing dioxin intake in e-waste recycling areas in China. In 2015, 42 mothers were recruited from an e-waste recycling site, and the same number of mothers were recruited from a reference site. We collected 10-mL breast milk samples from each participant. Breast milk concentrations of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) were significantly higher in the exposed group than in the reference group. The total toxic equivalents (TEQ) of PCDDs/DFs were 9.68 pg/g lipid in the exposed group, a value two times higher than those in the reference group (4.18 pg/g lipid). The estimated daily intake (EDI) of PCDD/DFs was calculated to assess the risk of dioxins through breastfeeding. The infant EDI level was two times higher in the exposed group (54.21 pg TEQ/kg body wt/day) than in the reference group (23.41 pg TEQ/kg body wt/day). Our findings suggest that mothers and their breastfeeding infants living in an e-waste recycling site were exposed to higher dioxin concentrations than those living in a reference site.

Lifetime Cadmium Exposure and Mortality for Renal Diseases in Residents of the Cadmium-Polluted Kakehashi River Basin in Japan.

Very few studies have investigated the dose-response relationship between external cadmium (Cd) exposure and mortality. We aim to investigate the relationship between lifetime Cd intake (LCd) and mortality in the Cd-polluted Kakehashi River basin in Japan. Mortality risk ratios for a unit of increase of LCd and urinary Cd were analyzed using Cox's proportional model. LCd was estimated based on residency and Cd in rice produced in their living areas. In men, mortality for all causes was significantly increased for a 10-µg/g Cr increase in urinary Cd, but not for a 1-g increase in LCd. In women, mortality risks for all causes and renal diseases, particularly renal failure, were significantly increased for a 10-µg/g Cr increase in urinary Cd. Similarly, mortality risks for renal diseases and renal failure were significantly increased for a 1-g increase of LCd in women. Comparing the contribution of two exposure markers to increased mortality in women, LCd was more effective for increasing mortality risks for renal diseases and renal failure, while urinary Cd contributed more to increased mortality risk for all causes. LCd may show a better dose-response relationship with mortality risk for renal diseases in women.

The relationship between perinatal exposure to dioxins and serum steroid hormone levels in preschool-aged children at an e-waste region in China.

Perinatal exposure to dioxins affects steroid hormone synthesis. The purpose of the present study was to evaluate the associations between perinatal exposure to dioxins and serum steroid hormone levels in preschool-aged children from an e-waste recycling region in China. In the present study, we enrolled 50 pairs of mothers and infants from the Taizhou, Luqiao region in 2015. Of the 50 pairs of mothers and infants, 42 pairs participated in this study when the children were 4 years old. We measured breast milk dioxin concentrations using high-resolution gas chromatography/mass spectrometry. Additionally, we used liquid chromatography-tandem mass spectrometry to measure the concentrations of progesterone, testosterone, androstenedione (A-dione), and dehydroepiandrosterone (DHEA) in serum samples from the 4-year-old children. We used multivariate linear regressions to assess the associations between dioxin congeners and steroid hormones. Results were reported as beta estimates and 95% confidence intervals by bootstrapping. We observed sex-related differences between breast milk dioxins and serum steroid hormone levels in 4-year-old children. An increase in breast milk dioxins was associated with a decrease in testosterone in serum samples from boys. Similarly, an increase in breast milk dioxins was associated with a decrease in progesterone levels in serum samples from girls. However, dioxins were not associated with changes in the levels of testosterone, DHEA, or A-dione in girls. Based on these results, we conclude that perinatal exposure to dioxins modifies steroidogenesis in preschool-aged children. However, the long-term impact of dioxins requires further large-scale studies to assess these effects in school-going children and adolescents.