AbstractContaminated food chain is a serious contender for arsenic (As) uptake around the globe. In Nadia, West Bengal, we trace possible means of transfer of As from multiple sources reaching different trophic levels, and associated seasonal variability leading to chronic As uptake. This work considers possible sources-pathways of As transfer through food chain in rural community. Arsenic concentration in groundwater, soil, rice, and vegetable-samples collected detected in different harvest seasons of 2014 and 2016. Arsenic level in shallow groundwater samples ranged from 0.1 to 354?µg/L, with 75% of the sites above the prescribed limit by WHO (10?µg/L) during the boro harvest season. High soil As content (~20.6?mg/kg), resulted in accumulation of As in food crops. A positive correlation in As conc. with increase over period in all sites indicating gradual As accumulation in topsoil. Unpolished rice samples showed high As content (~1.75?mg/kg), polishing reduced 80% of As. Among vegetables, the plant family Poaceae with high irrigation requirements and Solanaceae retaining high moisture, have the highest levels of As. Contaminated animal fodder (Poaceae) and turf water for cattle are shown to contaminate milk (0.06 to 0.24?µg/L) and behoves strategies, practices to minimize As exposure. 相似文献
When reproductive success is constant in one breeding phase, different tactics that increase variation in reproductive success
among individuals may evolve in other phases. For instance, in shorebirds, which usually have a limited clutch size of four
eggs, variation in reproductive tactics among individuals is expected either before egg-laying (e.g. diverse mating systems)
or after hatching of the young (e.g. diverse parental care). In this paper, I studied the pied avocet (Recurvirostra avosetta), a shorebird with a modal clutch size of four eggs, to test whether post-hatch chick adoption as an alternative tactic can
be linked to increased variation in annual reproductive success. When predation was high, naturally adopting pairs produced
more filial fledglings than did pairs not adopting chicks and not losing chicks to adoption. The number of filial fledglings
increased with the number of adopted young, possibly through diluting the chances of predation on filial young. Experimental
chick addition did not lead to more fledged young due to low brood integrity as shown by the frequent loss of chicks from
some experimental broods. When predation was low, larger broods occupied feeding territories with higher prey abundance than
smaller broods, possibly due to their dominance over smaller ones. Pairs that lost chicks to adoption (donors) fledged as
many filial young in their broods as did non-adopters/non-donors, whereas the total number of donors’ filial fledglings, including
those raised in adopting broods, approached that of adopters. These findings show, for the first time, that post-hatch alternative
reproductive tactics can lead to variation in annual reproductive success and to higher success for some pairs even in species
where past adaptations limit variation in reproductive success in a certain phase of reproduction. 相似文献
以闽中某矿区县茶园表层土壤(0~20cm)为研究对象,采集了25份茶园土壤样品,分析了土壤中重金属Cr、Ni、Cu、Zn、As、Pb、Cd和Co的含量,分别利用地累积指数法和潜在生态风险指数法对土壤重金属的污染现状和潜在生态风险程度进行评价;同时收集矿区茶叶企业23个商品茶样品,利用美国国家环保署(USEPA)推荐的健康风险评价模型进行人体重金属健康风险评价.结果表明:(1)矿区茶园表层土壤Cr、Ni、Cu、Zn、As、Pb、Cd和Co平均含量分别为110、23.5、23.0、107、50.7、78.0、0.23和14.3mg/kg,均明显高于福建省土壤背景值;(2)茶园土壤地累积指数(Igeo)表现为As > Cd > Cr > Pb > Zn > Co > Ni > Cu,As属于重度污染,Cd和Cr属于中度污染,其它5种重金属元素污染风险较低;(3)单项潜在生态风险系数(E)的大小顺序依次为Cd > As > Pb > Co > Ni > Cr > Cu > Zn,土壤Cd属于很强生态风险,土壤As属于较强生态风险,其余属于轻微生态风险.8种重金属综合潜在生态风险指数(RI)平均值为255.74,属于较强风险级别,Cd和As是最主要的潜在生态风险因子.(4)商品茶中重金属Cr和Cd含量均低于限量标准,个别茶样中Cu、As和Pb含量超标,说明茶叶中重金属含量总体处于安全级别;(5)健康风险评价结果表明,茶叶中重金属元素健康个人年风险总和为1.01×10-4~9.07×10-5,乌龙茶的个人年风险总和稍高于美国环境保护署(USEPA)推荐的最大可接受风险水平(1.0×10-4),红茶和绿茶低于USEPA推荐的最大可接受风险水平;茶叶中重金属元素健康风险以Cr为主,平均贡献率为90.38%,是主要的风险元素,其余重金属元素处于安全范围之内. 相似文献
Objectives: Motor vehicle collisions (MVCs) are a significant health burden in Saudi Arabia. The literature has consistently indicated that chronic medical conditions, such as diabetes, heart disease, stroke, obstructive sleep apnea, and neurodevelopmental disorders, increase the risk of MVCs. Therefore, assessment of driver fitness by primary care physicians (PCPs) remains a major health intervention that might reduce MVCs. We studied the practices of PCPs in assessing medical fitness to drive in at-risk patients.
Methods: We conducted a cross-sectional study of all 88 government-funded primary care centers in the city of Riyadh, Saudi Arabia. We administered a self-reported questionnaire to PCPs that inquired about their driving risk assessment for specific medical conditions.
Results: Among all PCPs and centers, 189 PCPs (63%) from 74 centers (84%) participated in our survey. The mean age of the PCPs was 40 ± 10 years, and 108 (57%) were men. The average clinical experience of the group was 13 ± 9 years. Fewer than half of PCPs considered diabetes mellitus (45%) and obstructive sleep apnea (46%) as potential risks for MVCs. Approximately 45% of PCPs did not notify any authority or relatives of potential driving issues that they noticed in their patients. Only 15% of the participants believed that PCPs were responsible for alerting authorities about their fitness to drive.
Conclusions: PCPs did not adequately assess their patients' driving history and eligibility. Efforts are needed to improve awareness among PCPs regarding the effects of chronic medical conditions on driving. 相似文献