铜和铅在污水鱼塘中鱼体内的蓄积

从天津污水鱼塘中采集了养殖的各种鱼,测定其鳃、肝、肾、肌肉等部位中的铜、铅蓄积量。并与水相金属形态化学平衡计算结果进行了比较。研究证实,铜、铅蓄积量在鱼体中呈对数正态分布,与不同鱼种无显著关系,但在各部位之间明显不同。由于吸收／排放的动力学差异,养殖后期鱼体中铅／铜蓄积比较中期低,反映了铅、铜相对蓄积速率的下降趋势。不同鱼塘鱼鳃的金属蓄积量与金属有效态含量呈正相关      

Conceiving a fetus for bone marrow donation: An ethical problem in prenatal diagnosis

We present a family who sought prenatal diagnosis in order to bear a healthy child to serve as an HLA–identical bone marrow donor for their son affected with Wiskott–Aldrich syndrome. They intended to abort HLA-incompatible fetuses who would have been unsuitable bone marrow donors. This case led us to conclude that prenatal diagnosis should not be used to benefit a third party or facilitate the conception or abortion of a fetus for the purpose of generating an organ for transplantation. The limits of parental autonomy and physician responsibility are discussed.     

Bioaccumulation Kinetics and Bioconcentration Factor of Chlorinated Pesticides in Tissues of Puntius ticto (Ham.)

Abstract

Bioaccumulation kinetics and bioconcentration factor (BCF) of chlorinated pesticides like Aldrin, Dieldrin, Benzene hexachloride (BHC), and Dichloro-diphenyl-dichloro-ethane (DDT) in fish tissues of Puntius ticto was studied in detail in a continuous fed system. The bioconcentration process is summarized by using a first order uptake model and the steady-state BCF is calculated based on the 30 days exposure. Rate of bioaccumulation of DDT was maximum of 4.6432 µg g^?1 wet weight per day in liver tissue whereas it was minimum of 0.0002 µg g^?1 wet weight per day in case of Dieldrin in the muscle tissue among the pesticides. It was observed that DDT showed maximum BCF of 89,010 in case of liver tissue of the fish exposed to 30 days. The regression coefficient (r ²) between pesticide concentration and exposure time varied between 0.6212 and 0.9817 indicating high correlation. Based on actual calculated BCF values, the octanol–water partition coefficient (K _ow) values were predicted. In order to prove the hydrophobic property of chlorinated compounds and its affinity towards lipid, the K _ow is predicted. Results showed that pesticide burden differ from tissue to tissue and can be correlated to the lipid content, size, exposure time, and species.     

Are motorcycles really “donorcycles”? Examining organ donation rates between unhelmeted and helmeted motorcyclists

Introduction: Motorcycles are colloquially referred to as “donorcycles” among medical staff. However, the actual impact of helmet laws and helmet use on organ donation is unknown. Michigan’s 35-year-old universal helmet law (UHL) was repealed in April 2012 and replaced by a partial-helmet law. We hypothesized that there would be an increase in organ donation rates from unhelmeted motorcyclist fatalities. Methods: Michigan's Gift of Life Michigan organ donation database was queried from April 2008 through May 2015 in conjunction with the Michigan Trauma Quality Improvement Program database from the same time period. All in-hospital motorcycle crash fatalities were examined. Results: A three-fold increase was found in the rate of organ donation for unhelmeted motorcyclists compared to helmeted motorcyclists (p = 0.006). Motorcycle crash fatalities tended to be younger in age after the UHL repeal with an average age of 32.8 years versus 40.8, however, this finding was not statistically significant (p = 0.071). Additionally, there was no significant difference in organ donation rates pre-UHL repeal (2008–2012) versus post-repeal (2012–2015). Conclusions: This is the first study to demonstrate an increased rate of organ donation among unhelmeted motorcyclist fatalities compared to helmeted rider fatalities. There was no significant increase in the rate of organ donation following the Michigan UHL repeal. However, we identified that some motorcycle crash fatalities were from illegally unhelmeted riders in the past, prior to the repeal. Practical Application: Unhelmeted motorcyclists are three times more likely than helmeted riders to become organ donors, possibly due to the well documented increase in severe traumatic brain injuries in this population. From a public health perspective, helmets should be required for all motorcyclists and efforts to advocate in favor of helmet legislation should be supported by trauma systems and health professionals.     

Doses of external exposure in Jordan house due to gamma-emitting natural radionuclides in building materials

The use of building materials containing naturally occurring radionuclides as ⁴⁰K, ²³²Th, and ²³⁸U and their progeny results in external exposures of the residents of such buildings. In the present study, indoor dose rates for a typical Jordan concrete room are calculated using Monte Carlo method. Uniform chemical composition of the walls, floor and ceiling as well as uniform mass concentrations of the radionuclides in walls, floor and ceiling are assumed.Using activity concentrations of natural radionuclides typical for the Jordan houses and assuming them to be in secular equilibrium with their progeny, the maximum annual effective doses are estimated to be 0.16, 0.12 and 0.22 mSv a⁻¹ for ⁴⁰K, ²³²Th- and ²³⁸U-series, respectively. In a total, the maximum annual effective indoor dose due to external γ-radiation is 0.50 mSv a⁻¹. Additionally, organ dose coefficients are calculated for all organs considered in ICRP Publication 74. Breast, skin and eye lenses have the maximum equivalent dose rate values due to indoor exposures caused by the natural radionuclides, while equivalent dose rates for uterus, colon (LLI) and small intestine are found to be the smallest. More specifically, organ dose rates (nSv a⁻¹ per Bq kg⁻¹) vary from 0.044 to 0.060 for ⁴⁰K, from 0.44 to 0.60 for radionuclides from ²³⁸U-series and from 0.60 to 0.81 for radionuclides from ²³²Th-series.The obtained organ and effective dose conversion coefficients can be conveniently used in practical dose assessment tasks for the rooms of similar geometry and varying activity concentrations and local-specific occupancy factors.     

水葫芦各部位富集能力的研究

通过对水葫芦根、茎、叶三部位脂肪、蛋白质、糖、钙、镁及重金属元素 (Fe、Cu、Pb、Zn、Cd、Cr)含量的测定 ,发现水葫芦茎、叶、根中脂肪、蛋白质、糖的含量无明显差异。整株植株营养价值与大白菜接近。金属元素在根部富集较多 ,而且其中大部分是吸附在根的表面。     

Legacies and health risks of heavy metals,polybrominated diphenyl ethers,and polychlorinated dibenzo-dioxins/furans at e-waste recycling sites in South China

● Heavy metals and organic toxins may persist in legacy sites for a long time. ● Contaminants pose potential harms to the nearby community (HI > 1). ● PCDD/Fs had the risk of endocrine disruption and reproductive risk. ● Further intervention is needed to reduce pollution and related risks. Informal electronic-waste (e-waste) recycling sites pose substantial health risks to surrounding environments and populations, yet they are not properly regulated. In this study, the soil levels of copper, lead, cadmium, eight polybrominated diphenyl ethers (PBDEs), and 18 polychlorinated dibenzo-dioxins/furans (PCDD/Fs) were measured at two e-waste recycling sites in South China between 2014 and 2019. Both sites have been abandoned for natural restoration. Our results indicate that the mean Cd and PCDD/F levels at Site A in 2019 were higher than those recommended by current safety guidelines. Meanwhile, the highest exposure among children was 1.36 × 10⁻² mg/(kg·d) for Cu, followed by 5.05 × 10⁻³ mg/(kg·d) for Pb, 9.71 ng/(kg·d) for PBDEs, and 6.82 ng TEQ/(kg·d) for PCDD/Fs. Children were at elevated risk for health problem posed by Pb and Cu exposure at both sites (hazard quotient > 1) and by PCDD/Fs at Site A. Further risk assessment was conducted on the target organs and endpoints of heavy metals and PCDD/Fs. The hazard index (HI) for the target organ mixed-risk of heavy metals was high (HI = 1.27), as was that of PCDD/Fs (HI = 1.66), which can disrupt endocrine function and pose a risk of reproductive toxicity in children. Owing to incomplete cleaning, contaminants persist in soils over long periods and may harm nearby environments and communities. Our study demonstrates that heavy metal, PBDE, and PCDD/F contamination have not yet been remediated, and intervention is needed to reduce pollution and associated risks in areas affected by e-waste.