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Issue 24
21st
December 2009
C&I Magazine
C&I MagazineThe leading source of news and opinion in the arena of chemical technology
Cover Story
Out of this world
Despite the myths about the lack of real scientific results from space
exploration, Neil Eisberg discovers that a wealth of real research has
been conducted by NASA and continues on the Space Station
News
Patrick Walter,
21/12/2009
Resolve is hardening in the US to
revamp and strengthen the Toxic
Substances Control Act (TSCA) as
the Environmental Protection Agency
(EPA) administrator, Lisa Jackson,
told a Senate Committee that the Act
was ‘outdated’ and did not have the
tools to protect the general public
and environment.
Andrew Turley,
21/12/2009
The US Environmental Protection
Agency (EPA) has concluded that
greenhouse gases (GHGs) ‘threaten
the health and welfare of the
American people’.
Features
Anthony King,
21/12/2009
That heady mix of pine needles, plum pudding and cooked turkey is more than
the sum of its parts, reports Anthony King. It is Christmas.
Lou Reade,
21/12/2009
Children’s traditional chemistry sets may be losing popularity, but there are
plenty of other chemistry-related toys for budding chemists. Lou Reade reports
Editor's Blog
Dose of poison
Agree or disagree? Post your views below
According to Paracelsus, ‘The dose makes the poison’; in other words, what matters is not so much the substance but how much of it is present. In modern usage, international regulators and scientific authorities have interpreted this by assigning to different chemicals so-called threshold values related to their observed or projected toxicities, below which doses we are led to believe they may be safely used and applied. LD50 values, at which concentration of substance half of the cells in a population will die, are another measure adopted to instil confidence that we have some handle on safety.
But can we be sure that staying below the recommended levels will keep us safe from adverse effects? With so many chemicals now circulating in the environment, is it wise to simply assume we are safe below a pre-assigned dose of any one of these without taking account of potential interactions with others?