20 September 2019 Bulletin

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Sodium Cyanide

SodiSodium cyanide is an inorganic compound with the formula NaCN. It is a white, water-soluble solid. Sodium cyanide is a deliquescent crystalline powder, which means that it has a strong affinity for moisture and will absorb relatively large amounts of water from the atmosphere if exposed to it, forming a liquid solution. [2] It often has a smell like bitter almonds, but not everyone can smell it due to a genetic trait. [3] It also has a high affinity for metals, which leads to the high toxicity of this salt. [1]

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Have your say to help EPA to protect the environment

Victorians can have their say on how risks to public health and the environment will be managed, as Environment Protection Authority Victoria (EPA) calls for comments on new environmental regulations and standards that will apply from July 2020. The new regulations and standards are part of the Victorian Government’s modernisation of Environment Protection Authority Victoria (EPA) through the newly passed Environment Protection Act. “The new Act and regulations will give EPA more power to prevent pollution and hold polluters to account,” EPA Executive Director Tim Eaton said. “Where the new Act lays out the increased powers and responsibilities, the regulations and standards fill in the details and create certainty for duty holders to meet their obligations,” Mr Eaton said. “The draft regulations set out obligations in relation to environment protection, pollution incidents, contaminated land and waste. They also offer duty holders a sense of certainty as they set out to meet their obligations to reduce the risk of harm to public health and the environment,” he said. As an example: the new EP Act allows EPA to require duty holders to be licensed, permitted or registered – the regulations then provide the detail of what activities will require a licence, permit or registration. The public comment period for the regulations and standards calls for feedback, which can be anything from a detailed technical submission to a simple suggestion from a member of the public and is open until the end of October. “We want to hear from community groups, industry, small business operators, anyone with an existing EPA licence, environmental lobby groups, or any other member of the public or industry with an interest in the environment protection laws” Mr Eaton said. “Have your say on proposed regulations and standards that relate to waste, permissions and licences, water, noise, air and contaminated land,” he said. You can see the draft regulations and standards on the EPA page on Engage Vic website from 2 September to 31 October 2019. “EPA and the Department of Environment, Land, Water and Planning (DELWP) will review all public submissions and there will be a public report that includes responses to the submissions, published alongside the final regulations and standards,” Mr Eaton said. EPA recommends that anyone making a submission should read the Guide to the Regulations first and focus their comments on the regulations and standards; the consultation doesn’t have the scope to address major, whole-of-Government policy matters. “Above all, have your say now. By contributing to the new laws that will take effect in 2020, you will be helping to shape the tools that protect the environment and public health for all Victorians,” Mr Eaton said.


Gel that makes teeth repair themselves could spell the end of fillings

Enamel is the hard, protective layer on the outside of teeth. It can be worn down by mouth acid and repeated chewing, leading to cavities that have to be plugged with fillings to prevent further decay. Because fillings are made from foreign materials like metal, porcelain and resin, they don’t bind seamlessly to the tooth surface and often become loose. To overcome this problem, Ruikang Tang at Zhejiang University in China and his colleagues made a gel containing calcium and phosphate – the building blocks of real enamel – to try to encourage teeth to self-repair. They tested the gel by applying it to human teeth that had been removed from patients and damaged with acid. They then left the teeth in containers of fluid designed to mimic the mouth environment for 48 hours.

New crystals During this time, the gel stimulated the growth of new enamel, with microscopy revealing that it had the same highly ordered arrangement of calcium and phosphate crystals as regular enamel. This is probably because in normal tooth development, the emerging enamel is coated in a disordered layer of calcium and phosphate particles – like in the gel – that encourages its growth, says Tang. The new enamel coating was only 3 micrometres thick, which is about 400 times thinner than undamaged enamel. But Tang says the gel could be repeatedly applied to build up this repair layer. Several other groups have tried to repair tooth enamel with calcium and phosphate mixtures, but they contained larger particle clusters that didn’t cling well to the tooth surface, says Tang. This made it difficult for the enamel crystals to re-build, he says. The team is now testing the gel in mice and hopes to later test it in people. They will need to make sure the chemicals in the gel are safe and that new enamel can form in the real-life mouth environment, even when people eat and drink, Tang says.


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