参考消息网报道 外媒称,美国航空航天局(NASA)6月16日公布的最新卫星资料显示,世界上最大的地下含水层中,三分之一的水位正在以惊人的速度下降,其中包括中国的地下含水层。 据台湾联合新闻网6月18日报道,主持研究的NASA喷气推进实验室水资源科学家法米列提指出:“情势非常严峻,全世界各地的地下水位都在下降。没有用之不竭的水。”这项研究刊载于16日出版的《水资源研究》期刊。 以下为刊登在《水资源研究》期刊上的研究摘要部分: 论文摘要 地下水资源是一种 有限的 资源。目前我们没有采取 可持续性 的方式采集地下水,这让整个含水层系统的恢复能力受到威胁,并使其丧失成为长期水源的可能性。虽然程度尚未被深入探讨,但地下水存储量是决定水层恢复能力的因素。在本研究中,我们对世界上最大的地下水系统进行遥感观测,并评估了 地下水层恢复能力 的极限。地下水总应力(TGS)比率,指的是总储水量与地下水消耗率的比率,可以在时间尺度上用来研究世界上最大的含水层系统和相关的地下水缓冲器容量的消耗率。研究发现,现有跨数量级、大规模地下水储量知识的不足,严重限制了对含水层恢复力特性的研究。此外,地下水的可用性大小(传统被定义为再补给,在本研究中重新定义为“总出水量”),可以改变水层系统是否应力以及应力大小。 美国航空航天局重力恢复和气候实验卫星(GravityRecovery and Climate Experiment satellites)提供了地下含水层最详细 的信息。举例来说,曾据此证明过:如果撒哈拉西北的一个含水层系统以每年2.69±0.8 km 3 的速度枯竭,将 导致 地下储量减少90%,这还是基于50年期,水含量初始值为70 km 3 最低估算 。版权所有 仿冒必究。 作者: Alexandra S.Richey, Brian F. Thomas, Min-Hui Lo, James S. Famiglietti, Sean Swenson, MatthewRodell 点击查看该篇论文: http://onlinelibrary.wiley.com/doi/10.1002/2015WR017351/full
据美国路透社消息,FDA 已正式发布公告:建议限制苹果汁中 无机 砷的含量,并标示与日常饮用水 旳砷含量水平相当; 该含 量定为十亿分之十(10ppb),与美国环境保护署规定的饮用水中含量是一样 的。 无机砷不仅在天然产物,如中药砒霜中有,就连喷洒农药后的蔬菜、药用植物,以及人们日常用的食 品 中都能检 测出,还与心血管疾病、糖尿病、神经性损伤、发育性疾病、皮肤中毒有关,并已证明是致 癌 物! FDA已持续20年之久留样观察苹果汁,证明有微量的无机砷的含量,而且是被非盈利的、多方参与的消 费者组织所验证。官方和民间同时监督检验方才公布!国内是否可借鉴一下。 下面是英文报道“ (Reuters) - The U.S. Food and Drug Administration has proposed to put a limit on the amount of inorganic arsenic found in apple juice, comparable to the allowed level of arsenic in drinking water. The FDA has proposed a limit of 10 parts per billion (ppb) for inorganic arsenic in apple juice. This is the same level set by the U.S. Environmental Protection Agency (EPA) for arsenic in drinking water. Inorganic arsenic may be found in foods as it is present in the environment, both as a naturally occurring mineral and due to activities such as the use of arsenic-containing pesticides. A known carcinogen, inorganic arsenic has also been associated with skin lesions, developmental effects, cardiovascular disease, neurotoxicity and diabetes. "While the levels of arsenic in apple juice are very low, the FDA is proposing an action level to help prevent public exposure to the occasional lots of apple juice with arsenic levels above those permitted in drinking water," said FDA's deputy commissioner for foods and veterinary medicine, Michael Taylor. The FDA has been monitoring the presence of arsenic in apple juice for the past 20 years and has consistently found that samples contain low levels of arsenic, with few exceptions, the agency said on its website. The proposal was applauded by non-profit, independent product-testing organization Consumer Reports, which called it a "reasonable first step in protecting consumers from unnecessary exposure to arsenic. "Now that the FDA has released its proposed guidance, we look forward to analyzing the agency's risk assessment, submitting comments, and continuing the dialogue on this important public health issue," said Urvashi Rangan, Director of Consumer Safety and Sustainability at the organization.”