Maternal exposure to high levels of dioxins in relation to birth weight in women affected by Yusho disease

Background

Studies on the association of maternal exposure to polychlorinated dibenzo-p-dioxin (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) with decreased birth weight in humans have produced conflicting results. In Japan in 1968, an accidental human exposure to rice oil contaminated with PCDDs, PCDFs, and PCBs, led to the development of Yusho disease.

Objective

The Yusho cohort was used to evaluate the effect of maternal exposure to PCDDs, PCDFs, and PCBs on birth weight.

Methods

Blood samples, obtained from 101 Yusho women (190 births) who gave birth after exposure, were analyzed for congeners of seven PCDDs, ten PCDFs, and four non-ortho PCBs.

Results

Total PCDD TEQ (adjusted beta = − 161.9 g; 95% CI, −265.3 to − 58.6), total PCDF TEQ (adjusted beta = − 105.9 g; 95% CI, −179.5 to − 32.2), and total non-ortho PCBs (adjusted beta = − 178.4 g; 95% CI, −318.3 to − 38.5) levels were inversely associated with birth weight. Significant inverse associations with birth weight were also found for total PCDD TEQ, total PCDF TEQ, and total non-ortho PCB TEQ levels among male, but not female, infants. Significant inverse associations with birth weight were also found for nine congeners among all infants; the adjusted beta coefficients were largest for 1,2,3,6,7,8-HxCDD and smallest for 2,3,4,7,8-PeCDF.

Conclusion

In the setting of exposure to high levels of dioxins, maternal blood levels of PCDDs, PCDFs and PCBs are associated with lower birth weight in Yusho patients. The association exhibited gender-specific differences, as male infants are more susceptible than females to growth restriction induced by in utero dioxin exposures.     

Comparison of the concentrations of polychlorinated biphenyls and dioxins in mothers affected by the Yusho incident and their children

Accumulated maternal dioxins are passed onto the fetus and neonate via the placenta and maternal milk. In Japan in 1968, an accidental human exposure to rice oil contaminated with polychlorinated biphenyls (PCBs) and other dioxin-related compounds, such as polychlorinated dibenzofurans (PCDFs), led to development of Yusho oil disease. We investigated differences in blood dioxin concentrations in mother-children pairs affected by the Yusho incident. From 2002 to 2008, blood samples were collected from 26 pairs of Yusho mothers and their children (19 mothers, 26 children). Specific congeners of seven polychlorinated dibenzo-p-dioxins (PCDDs), ten PCDFs, and four non-ortho PCBs were analyzed. The children had significantly lower TEQ concentrations of PCDDs, PCDFs, and coplanar PCBs compared to their mothers. The mother-child difference in blood concentrations varied with the congeners; the largest for 2,3,4,7,8-pentaCDF and the smallest for 1,2,3,4,6,7,8-heptaCDD. The level for 2,3,4,7,8-pentaCDF, which characterizes Yusho oil disease, was approximately 17-30 times higher in the mothers than in the general population, whereas there were no significant differences between children in the formula-fed group and the general population. In contrast, the mean level for 2,3,4,7,8-pentaCDF in the breast-fed group was approximately 1.5 times, (range 0.5-6.5 times) higher than that in the general population. Over 30 years after the Yusho incident, the mean blood dioxin levels in the offspring were only a fraction of the levels in their mothers. This is more consistent with exposure via breast milk than via transplacental transfer in the Yusho incident.     

Compound-specific isotopic and congener-specific analyses of polychlorinated biphenyl in the heat medium and rice oil of the Yusho incident

Compound-specific isotope analysis (CSIA) can be used to examine the source and transformation processes of organic pollutants in the environment. We performed a carbon stable isotope analysis of polychlorinated biphenyl (PCB) congeners in the PCB heat-transfer medium (heat medium) and the original Kanechlor-400 (KC-400, a commercial brand of PCBs) involved in the Yusho incident. The main purpose is to investigate whether isotope fractionation occurred in the rice oil deodorization process that caused the incident. The carbon isotope ratios (δ¹³C values) of the targeted PCB congeners ranged from ? 29.39 to ? 27.00‰ in the heat medium and from ? 28.77 to ? 27.05‰ in the original KC-400. No significant differences were found in the δ¹³C values, suggesting carbon isotope fractionation did not occur for the targeted PCB congeners in the heat medium when deodorization of rice oil occurred at temperatures above 200 °C. Furthermore, we also conducted a congener-specific analysis of 64 PCB congeners found in the heat medium and rice oil contaminated by it. The total PCB congener concentrations were 503 mg/g in the heat medium and 81 μg/g in the rice oil. The concentrations of the highly chlorinated congeners were significantly lower in the heat medium than in the original KC-400, and the compositional ratios of the lowly chlorinated congeners were relatively lower in the rice oil than in the heat medium. These results suggest that the PCB congener patterns gradually changed from that of the original KC-400 in the deodorization process and subsequent contamination into the rice oil. Thus, a combination of CSIA and congener-specific analysis is a new approach for investigating the changing PCB congener profiles in samples from the Yusho incident.     

Thermal destruction of wastes containing polychlorinated naphthalenes in an industrial waste incinerator

A series of verification tests were carried out in order to confirm that polychlorinated naphthalenes (PCNs) contained in synthetic rubber products (Neoprene FB products) and aerosol adhesives, which were accidentally imported into Japan, could be thermally destroyed using an industrial waste incinerator. In the verification tests, Neoprene FB products containing PCNs at a concentration of 2800 mg/kg were added to industrial wastes at a ratio of 600 mg Neoprene FB product/kg-waste, and then incinerated at an average temperature of 985 °C. Total PCN concentrations were 14 ng/m³N in stack gas, 5.7 ng/g in bottom ash, 0.98 ng/g in boiler dust, and 1.2 ng/g in fly ash. Destruction efficiency (DE) and destruction removal efficiency (DRE) of congener No. 38/40, which is considered an input marker congener, were 99.9974 and 99.9995 %, respectively. The following dioxin concentrations were found: 0.11 ng-TEQ/m³N for the stack gas, 0.096 ng-TEQ/g for the bottom ash, 0.010 ng-TEQ/g for the boiler dust, and 0.072 ng-TEQ/g for the fly ash. Since the PCN levels in the PCN destruction test were even at slightly lower concentrations than in the baseline test without PCN addition, the detected PCNs are to a large degree unintentionally produced PCNs and does not mainly stem from input material. Also, the dioxin levels did not change. From these results, we confirmed that PCNs contained in Neoprene FB products and aerosol adhesives could be destroyed to a high degree by high-temperature incineration. Therefore, all recalled Neoprene FB products and aerosol adhesives containing PCNs were successfully treated under the same conditions as the verification tests.     

Performance and efficiency of removal of pharmaceutical compounds from hospital wastewater by lab-scale biological treatment system

The fate of pharmaceuticals after discharged from hospital into wastewater was clarified experimentally by using a new lab-scale conventional activated sludge (CAS) treatment reactor. The 43 target compounds belong to nine therapeutic classes (antivirals, antibacterials, anticancer drugs, psychotropics, antihypertensives, analgesic–antipyretics, contrast media, herbal medicines, and phytoestrogens) were selected with inclusion of 16 newly estimated compounds. The efficiency of the present reactor was estimated by comparing the reaction rate constant of the solid-water partition coefficients (log K_d) between liquid and solid samples and half-life during 48-h experiment obtained by using hospital effluents with those obtained by using STP wastewater. The results that no significant difference in removal efficiency was observed between both water samples (P?>?0.05) indicate high reliability of the present lab-scale reactor. The actual rates of removal when hospital effluent was applied varied widely (mean, 59?±?40%) independent of type of the pharmaceuticals. More than 90% of 17 compounds were removed after 8 h of treatment. However, the values for psychotropics (mean, 19?±?26%) and contrast media (mean, 24?±?17%) were generally low, indicating high stability. The log K_d values ranged from 1.3 to 4.8. Notably, clarithromycin, acridine, and glycitein could be removed in both liquid and solid phases. The dominant removal mechanisms were found to be different for individual pharmaceutical. These results suggest the effectiveness of introduction of the lab-scale biological treatment system for development of a new solution for discharge of pharmaceuticals from hospital.

     

Developing joint educational programs in sustainability science across different universities: a case study from Japan

The challenge for sustainability educational programs lies in how to imbue students with the strong motivation necessary to move the world in a more sustainable direction. Five universities in Japan have mutually collaborated in the design and development of a unique curriculum and education system for sustainability science since 2008. Specifically, they have developed a common and remote lecture system called the “Frontier of sustainability science” (FSS). This paper discusses the concepts and challenges of FSS and how it was organized to teach students to actively learn how to work with people of various disciplines to realize interdisciplinarity.     

Laboratory studies of the diffusive transport of Cs and Co through potential waste repository soils

Tests using reconstituted samples have been performed to assess the diffusive transport of ¹³⁷Cs and ⁶⁰Co through natural regolith materials from a region in South Australia being considered for a radioactive waste repository. A double diffusion cell apparatus made of polycarbonate resin was developed to estimate the effective diffusion (D_e) and sorption coefficients (K_d) that allowed large withdrawals from the source and collector cells and has enabled tests with low concentrations of radioactivity. An alternative to porous stainless steel filter plates has also been used to reduce uncertainty in test interpretation. Analysis of the transient data used a staged method of the Laplace transform to take into consideration the volume of the samples withdrawn from the apparatus during testing. At test completion samples were cut into slices and analysed for radionuclide concentration. Data obtained from the sliced samples confirmed that both numerical and experimental data produced acceptable mass balance. The D_e values obtained in this study were of the order of 10⁻⁶ cm² s⁻¹ for both species, higher than previously published data. The K_d values from the diffusion and batch sorption tests were in reasonable agreement for ¹³⁷Cs, but an order of magnitude different for ⁶⁰Co. The sorption of the latter radionuclide was strongly pH dependent, and this dependency during diffusion tests would benefit from further investigation.     

Impact of the December 2004 tsunami on soil, groundwater and vegetation in the Nagapattinam district, India

The tsunami of 26 December 2004 struck the Nagapattinam District, Tamil Nadu, India. Sea water inundation from the tsunami caused salinization problems for soil and groundwater in coastal areas of the district, and also induced salt injuries in crops. To document the recovery of the agricultural environment from the tsunami, we conducted observations of the soil, groundwater, and vegetation. Soil electrical conductivity increased sharply after the tsunami, but returned to pre-tsunami levels the following year. Groundwater salinity returned to pre-tsunami levels by 2006. These rapid rates of recovery were due to the monsoon rainfall leaching salt from the highly permeable soils in the area. MODIS NDVI values measured before and after the tsunami showed that vegetation damaged by the tsunami recovered to its pre-tsunami state by the next rice cropping season, called samba, which starts from August to February. From these results, we conclude that the agricultural environment of the district has now fully recovered from the tsunami. Based on the results, we have also identified important management implications for soil, groundwater, and vegetation as follows: 1) due to the heavy monsoon rainfall and the high permeability of soils in this region, anthropogenic inputs like fertilizers should be applied carefully to minimize pollution, and the use of green manure is recommended; 2) areas that were contaminated by sea water extended up to 1000 m from the sea shore and over pumping of groundwater should be carefully avoided to prevent inducing sea water intrusion; and 3) data from a moderate resolution sensor of 250 m, such as MODIS, can be applied to impact assessment in widespread paddy field areas like the Nagapattinam District.     

Sustainability education and a new master’s degree, the master of sustainability science: the Graduate Program in Sustainability Science (GPSS) at the University of Tokyo

The University of Tokyo started its Graduate Program in Sustainability Science (GPSS), offering a master of sustainability science degree, in 2007. The GPSS curriculum consists of: (1) knowledge and concept oriented courses, which cover sustainability-related subjects from a holistic viewpoint; (2) experiential learning and skills oriented practical courses, which offer practical exercises to acquire the skills and sensibility required of future leaders; and (3) the Master’s thesis, for which students are encouraged to address complex sustainability problems through a transdisciplinary approach. Sustainability science is not a discipline that can be defined simply by the subjects it deals with, but is an academic field characterized by core principles that include holistic thinking, transdisciplinarity, and respect for diversity. The GPSS has been designed so that students may gain the capacity to understand and practice these principles. The present paper describes how the GPSS has defined sustainability education and designed its curriculum accordingly.