Edible paint, Indian injustice and past memories

Clearing up cadmium confusion

From Philip Ball

In his letter, Mark Booth is quite right to imply that, when in my article on colour I wrote ‘The possibility that cadmium red might be removed from the market because of its toxicity…’, the word ‘its’ should more properly have been replaced with ‘cadmium’s’. Even though the jars of cadmium red pigment from the colourmakers Cornelissen come plastered with warnings, the pigment itself is indeed considered non-toxic because of its low solubility.

However, I am surprised that Booth, being in the pigment industry, does not know the basis of calls for use of cadmium red to be restricted. It is not that regulators make the simplistic assumption that all compounds of a toxic metal must themselves be toxic. Rather, the concern is that degradation of the compound in disposal and incineration might convert it to more bioavailable forms of cadmium. My own view, for what it is worth, is that this is an excessively cautious approach for an artist’s material, and one that moreover is expensive and thus used in moderation. While there is certainly chemical ignorance around, it scarcely helps to start seeing it where it does not exist.


London, UK

Saucy artwork

From Ronald Lewin

Firstly may I congratulate you on Chemistry World July 2014 for bringing together so many aspects of the strong links between chemistry and art. As a fellow and one who is involved in the arts, part of my work has been the design and delivery of the Young Scientist of the Year finals in Berkshire, sponsored by Dulux. The challenge for the six finalists was titled ‘Let’s make paint’. Who better to design and run the project than a group of expert young scientists from Dulux.

During the initial design phase, the importance of paint viscosity was raised, and so we needed to make a simple viscometer available to the students. I was given the task to design and make a viscometer with different substances; items that came easily to hand were water, tomato ketchup, custard and mayonnaise. As my investigation progressed, it occurred to me that it would be interesting to use these materials to paint works of art. 

I set up my canvas and easel, and with bowls of ketchup, custard and mayonnaise started my new life as an artist. At this time, the Higgs boson had recently been discovered, so I took this as my inspiration. What an opportunity to offer my friends a metaphor of this remarkable achievement at CERN, which is unintelligible to most of us, and to present it in a visual form.

The final work was entered for the Royal Academy Summer Exhibition this year, but sadly rejected by the academicians. How they could have assessed the work is difficult to understand. Apart from the title they had no idea that it was probably the first work of art ever to be offered to the Academy to celebrate the topical subject of the Higgs boson.

Neither did they realise that – like the Higgs particle – the life time of the picture is rather short and will have been lost forever by the time of the Summer Exhibition next year. 

R Lewin CChem FRSC

Princes Risborough, UK

Plaudits for Poliakoff

From Andres Tretiakov 

I am a chemist working as a laboratory technician at St Paul’s School in London. I am writing to you to congratulate you for an excellent and inspirational profile story.

I was fortunate enough to have met Martyn Poliakoff a few times, being just another fan of the Periodic Table of Videos. After reading the article I admire him even more, especially now I know a bit more about his background, achievements and the remarkable work he has done and is still doing.

He is truly a role model of our age and I only wish more people, more scientists and especially more chemists, followed his insatiable drive to make a better world and better living through chemistry.

Poliakoff’s stimulating and encouraging words always make my efforts feel worthwhile, and ignite in me and many others his contagious passion for chemistry. For this and many other reasons he deserves to be on the cover and I wish him and his team many more successful endeavours.

A Tretiakov RSci MRSC

London, UK

Certain about BPA

From Jacques Ragot

The overall impression regarding the safety of BPA (Bisphenol A) in your recent podcast is of complete uncertainty. This is not a fair reflection of the current status of risk assessment on BPA. The author refers to a review from 2010 by the World Health Organization (WHO) to support the claim that the science is ‘inconclusive and contradictory’.

However, in its 2010 report, the WHO identified a lot of certainty and established knowledge. In its conclusions, the WHO does not see any health concern for the vast majority of endpoints. Some uncertainties are raised that require additional research only for some unconventional endpoints in a few studies.

Lots of robust data on the above mentioned uncertainties is now available, in particular from an extensive US governmental research programme started in 2008 about the safety of BPA. To date, 20 papers have been published in the peer-reviewed scientific literature, with more expected when ongoing studies are completed. Those studies included a large-scale subchronic toxicity study that found no low-dose effects; metabolism studies that concluded BPA is efficiently metabolised and rapidly eliminated in adult humans; and developmental neurobehavioural studies that showed no adverse effects. Taken together, the findings from these studies provide strong support for the safety of BPA and, conversely, provide no basis for any regulatory or legislative actions.

Thus instead of using only the 2010 WHO report, it would have been better to rely on the latest reassessment from the US Food and Drug Administration considering US government research (‘Is BPA safe? Yes’, June 2013) or the latest draft opinion of the European Food Safety Authority (‘the exposure even for the highest exposed groups in the population is well below the t-TDI of 5µg/kg bodyweight per day, indicating that the health concern for BPA is low at the current level of exposure’; January 2014).

I believe we should not mix uncertainty and confusion. Uncertainty is a natural part of any scientific process. For BPA the additional studies have decreased the uncertainty and allow us to conclude on the safety of BPA. The podcast unnecessarily adds confusion to a debate already quite heated.

For transparency please note that I work for a large manufacturer of high performance polycarbonate, which is based on BPA.

J Ragot CChem MRSC 

Leverkusen, Germany

Injustice in India

From Debabrata Banerjea

In the report titled ‘Indian scientists call for commitment to science’, Mathai Joseph advocates creation of a public agency for research funding in India, without government control, to help eradicate the maladies that are impeding good quality research in the sciences. I am, however, not fully in agreement with his assessment of the problem, or the remedy he has proposed.

Any agency, whether government, quasi-government or public, has to depend on the recommendations of its duly constituted assessment committees for research funding, and I believe this is the situation anywhere in the world.

After my college and university education in India and postdoctoral research at Northwestern University, US, I started my career in India as a researcher and teacher. During the years until my retirement in 1995, I have witnessed with dismay people who, irrespective of their genuine academic worth, developed close relationships with those in positions of authority, and managed to bag the lion’s share of research funding provided by various agencies. A handful of people (some of whom were genuinely reputable scientists, but not all) served as members of assessment committees, and mostly distributed support to their favourites, depriving many more deserving applicants. These people in turn have been doing the same, initiating a chain reaction.

I do not say that all of our scientists are guilty of such acts of favouritism, nepotism and corrupt practice; but just as a few drops of a poison can make a large pot of milk unfit for consumption, a few dishonest persons can damage the entire system. Many who have a high level of honesty and integrity are, of course, guilty of not raising their voices against the continuing evils, thereby indirectly helping the situation to continue. Unless the mindset of members of our academic and scientific community changes, nothing better will happen in the foreseeable future. 

Before independence, good quality scientific research was carried out in the few universities then in existence, as well as in a few research institutes that were set up by individuals. Then, the emphasis was more on fundamental research. The situation changed after independence, when a chain of national laboratories was set up under the Council of Scientific and Industrial Research with disproportionate emphasis on applied research. The universities engaged in fundamental research were ignored, leading to a decline in academic output.

Interference by political parties also accelerated the academic decline in the universities in post-independence India. The acts, statutes and ordinances for management of the state universities have been so redrafted that all appointments from the vice-chancellor to faculty members are under remote political control. In the process, academically undeserving persons are easily admitted, depriving 

the most deserving ones. The central universities under the University Grants Commission are no better off. 

D Banerjea CChem FRSC

Kolkata, India

Sparking a memory

From Donal F Phillpotts

The diagram of Martin’s columns in August’s ‘Classic kit’ brought back memories of a mixed kind.

When I joined the research department of Imperial Group in 1958, a gas chromatograph of this type had been built and installed. I soon found myself put in charge of it. The detector was a gas density balance, I think designed and built by Martin and James. This is an elegant device but at its heart is a double thermocouple consisting of about 5mm of nichrome wire, fused at each end to a length of copper wire, the diameters being about 0.1mm.

The junctions were made by generating a spark on a metal plate. The first junction was fairly easy, but making the second usually destroyed the first. Even when the two junctions were achieved, mounting the thermocouple in the detector and effecting the contacts often broke it, necessitating a fresh start.

My sanity was eventually saved by the advent of the Pye Argon Chromatograph, with a detector invented by James Lovelock, which proved such a reliable workhorse that we bought several and laid the Martin and James model to rest.

D F Phillpotts CChem MRSC

Bristol, UK