Paul Williams (Educator)
Lecturer in Soil & Environmental Biogeochemistry
Paul, an analytical and environmental chemist, has research interests orientated around the role of soils & rhizospheres in global food security.
Activity
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Ted, thanks for your question. What you are referring to is the solute flux across the root plasma membrane. This indeed commonly relies on H+ ATPases. For rice especially H+ are released from roots to balance excess intake of cations over anions, due to the primary N source being NH4+. However, there’s a step in the process, before this, which is the element...
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Ted, thank you for your question. Just to clarify the point, the main take home message here is that total solubility of iron (at environmentally relevant ranges, i.e. 5-8) is low. Indeed there was a typo, the units for total ionic iron should have been 10 to the minus 15 M. Usually under oxidizing conditions iron readily precipitates as...
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Ted, you raise a good point. Based on the IUPAC definitions you are correct. However, Zn is often commonly grouped together with other transition elements in plant metallomics studies, see example below:
Metallomics. 2013 Sep;5(9):1090-109. doi: 10.1039/c3mt00086a.
Transition metals in plant photosynthesis.Perhaps, post-transition metal is a better...
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Paul Williams (Educator) made a comment
Here's an example of a rice producer that's not shying away from mentioning arsenic on the product label. Is this the way forward?
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In Mauritius, Gourmet Rice Points to a Brighter Future
http://www.nytimes.com/2015/10/20/business/energy-environment/in-mauritius-gourmet-rice-points-to-a-brighter-future.html?_r=0 -
Paul Williams (Educator) made a comment
For high density urban conurbations, could roof-top aeroponics play a role in supplying micro-nutrient rich foods/vegetables to local communities?
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Paul Williams (Educator) made a comment
Could simply cooking with a cast-iron skillet provide an answer to combating Fe deficiency?
Here's a study conducted in rural Cambodia:
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Paul Williams (Educator) made a comment
Iron supplementation has the potential to help many people, however care is also needed.
There is a hereditary condition in which excessive amounts of iron are absorbed from the diet.
Haemochromatosis is especially prevalent among those of Irish & Celtic descent...
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Paul Williams (Educator) made a comment
Could the "System of Rice Intensification (SRI)" be a solution?
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Paul Williams (Educator) made a comment
For those of you wishing to learn more about Selenium.. please check out the
"International Society For Selenium Research"
(www.seleniumresearch.org) -
Paul Williams (Educator) made a comment
Are there any readers from Brazil? I've heard some good things about the "Restaurant Populars" or "People's Restaurants". Could this be a model system to be adopted by other countries to help tackle MN deficiencies in urban settings? Should every country have a national food safety-net?
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Paul Williams (Educator) made a comment
Are we forgetting or losing important nutritional information as lifestyles change and traditional food cultures are eroded? Is there a role for underutilized crops in tackling micronutrient deficiencies?
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Paul Williams (Educator) made a comment
What’s the social cost of iron deficiency anemia in young children? This new study looks at this question with a case study set in India.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0136581
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Yusuf, many thanks for the link. Have you heard about "Golden Rice".. the project won a Patents for Humanity award this year..
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Paul Williams (Educator) made a comment
Could nano-particle fertilizers be used to combat micronutrient deficiencies?
Interesting new review on the subject:
(http://www.sciencedirect.com/science/article/pii/S0048969715001266)
Development and application of new types of fertilizers using innovative nanotechnology are one of the potentially effective options of significantly enhancing the...
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Hi Sofia, for a European arsenic map - try the link below
http://eusoils.jrc.ec.europa.eu/foregshmc/
It loads up into Google Earth so you need to download this first.
Other good maps include:
>The London soil As map
http://www.bgs.ac.uk/downloads/start.cfm?id=2020>The advanced soil geochemical atlas of England and...
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Paul Williams (Educator) made a comment
Early kidney damage in a population exposed to cadmium and other heavy metals.
Environ Health Perspect. 2009 Feb;117(2):181-4. doi: 10.1289/ehp.11641. Epub 2008 Sep 9.
http://www.ncbi.nlm.nih.gov/pubmed/19270785Abstract: Exposure to heavy metals may cause kidney damage. The population living near the Avonmouth (UK) zinc smelter has been exposed to...
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Apologies. The audio should have stated "England/Wales" as having the highest average levels.
Soil Cd map of Europe.
http://eusoils.jrc.ec.europa.eu/library/Data/Foregshmc/Cadmium.htm -
Paul Williams (Educator) made a comment
Another useful FAO report on arsenic in rice, with a focus on Bangladesh.
Arsenic contamination of irrigation water, soil and crops in Bangladesh: Risk implications for sustainable agriculture and food safety in Asia
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Paul Williams (Educator) made a comment
Some rice producers publish their rice testing plans & findings. Is this something that should be done more widely?
http://www.lundberg.com/info/arsenic-in-food/#arsenic-testing-plan
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Could soil bacteria reduce arsenic levels in rice?
http://www.designntrend.com/articles/19733/20140918/using-bacteria-combat-arsenic-rice.htm
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Hi Kirsten,
Excellent question. Here is how the grains were measured.
The rice samples were classified according to grain size and shape by taking their average L and L to B ratio into four categories viz short-bold (SB, L <5.50 mm, L/B <1.1−2), medium-slender (MS, L = 5.51−6.60 mm, L/B >3), long-slender (LS, L = 6.61−7.50 mm, L/B >3), and extra-long...
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Hi Maria,
Thanks for your question. There’s now a wide range of methods available to measure arsenic in foods. Some just give total arsenic (i.e. organic [As] + inorganic [As]), others are more advanced and are able to distinguish the different species in detail.
We haven’t gone into analysis methods here. However, there is a brand new free webinar...
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Part-2: Total arsenic concentrations in adult urine reached a maximum of ca. 550 μg L−1 (mean 220.2 μg L−1) after 16 h post-ingestion of realgar wine, while face painting caused arsenic levels in children's urine to soar to 100 μg L−1 (mean 85.3 μg L−1) 40 h after the initial paint application. The average concentration of inorganic arsenic in the urine of...
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Paul Williams (Educator) made a comment
Would you drink arsenic wine?
Environ Int. 2011 Jul;37(5):889-92. doi: 10.1016/j.envint.2011.02.020. Epub 2011 Mar 29.
http://www.sciencedirect.com/science/article/pii/S0160412011000559A cultural practice of drinking realgar wine leading to elevated urinary arsenic and its potential health risk.
Part-1: Toasting friends and family with realgar...
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Paul Williams (Educator) made a comment
Traditional herbal medicines are naturally occurring, plant-derived substances with minimal or no industrial processing that have been used to treat illness within local or regional healing practices. However can they also be elevated in arsenic?
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Paul Williams (Educator) made a comment
Could yogurt hold the key to protecting pregnant women from arsenic and other toxic trace elements?
Randomized Open-Label Pilot Study of the Influence of Probiotics and the Gut Microbiome on Toxic Metal Levels in Tanzanian Pregnant Women and School Children
http://mbio.asm.org/content/5/5/e01580-14.full -
Paul Williams (Educator) made a comment
Food-aid rice drink has high levels of arsenic
"EATING rice bran - a "superfood" - may increase exposure to the carcinogen arsenic. The news is particularly worrying as the bran is given to malnourished children in poor countries as a food supplement..."...
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Paul Williams (Educator) made a comment
Could nano-particle fertilisers be used to combat micronutrient deficiencies?
http://www.nature.com/srep/2014/140714/srep05686/full/srep05686.html
Some soluble phosphate salts, heavily used in agriculture as highly effective phosphorus (P) fertilizers, cause surface water eutrophication, while solid phosphates are less effective in supplying the...
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Paul Williams (Educator) replied to Ousman M Jarju
Many thanks Husnaa for your question.
This video below from the Canadian Hemochromatosis Society gives a good overview of “iron overload”, and what the health effects are?
http://www.toomuchiron.ca./video/ -
There is also a lot of activity in the US.
http://www.udel.edu/udaily/2015/sep/seyfferth-nsf-career-092314.html
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There's lots of work at the moment in China - looking at how to reduce As in rice.
http://twas.org/zhu-yongguan-2013-twas-prize-winner-agricultural-sciences
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Perhaps arsenic loading to paddy fields in Bangladesh can be reduced by "bund sealing", plus this also reduces methane emissions. For more information have a look at this recent study:
Sealing Rice Field Boundaries in Bangladesh: A Pilot Study Demonstrating Reductions in Water Use, Arsenic Loading to Field Soils, and Methane Emissions from Irrigation...
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Consumption of Brown Rice: A Potential Pathway for Arsenic Exposure in Rural Bengal
http://pubs.acs.org/doi/abs/10.1021/es204298aThis study assesses the arsenic (As) accumulation in different varieties of rice grain, that people in rural Bengal mostly prefer for daily consumption, to estimate the potential risk of dietary As exposure through rice intake....
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Hi Lawrence, a very interesting comment.
Do traditional practices and "ways of life" in the main help to protect against micronutrient deficiencies? Do we need to pay more attention to lessons learnt in our past or is the solution going to be a high tech one? i.e. breeding, new fertilisers, precision farming etc.. I wonder what everyone thinks?
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Thanks Martin for your response – you’re very close. Colocasia & rice tend to go hand in hand, where you find one the other is often not far away. Colocasia is commonly grown at the boarders of rice paddies in Asia. You can eat the shoots and leaves, but it’s the tubers that are more popular. I’ve been told by my colleagues in Bangladesh that traditionally...
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Sorry for the confusion, and thanks Kirsten for spotting this.. the true value should be 20 mg Se g.. which is still an awfully high concentration.
Has anyone tasted milk vetch before? You can make quite an acceptable, albeit somewhat earthy, tasting tea from it.
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Glossary - PART 3
-Mitochondria: an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It has a double membrane, the inner part being folded inwards to form layers (cristae).
-Oxides: An oxide is a chemical compound that contains at least one oxygen atom and one other element in...
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Glossary – PART 2
- Hemeproteins: The component of haemoglobin (and other hemeproteins) responsible for binding oxygen, consists of an iron ion that binds oxygen and a porphyrin ring that binds the globin molecules; one molecule binds one molecule of oxygen. (http://hemeprotein.info/heme.php).
- Molar concentration: is defined as the amount of a...
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Glossary – PART 1
- Chelates: Chelation describes a particular way that ions and molecules bind metal ions. Chelation involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central atom.
- Chloroplasts: are organelles, specialized subunits, in plant and algal cells. Their...
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Dear All,
Thank you for your patience - please find below a new glossary section.
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Hi Tom,
Good question. Maybe we are growing the wrong crops in some areas.
There are lots of underutilized plant species perfectly adapted to specific environs.. that we could be making a lot more use of.
Here’s one organization that certainly think this to be the case..
Crops for the Future..
http://www.cropsforthefuture.org/ -
Hydroponics could be an option - but it would make make growing rice very expensive.
Have you heard of aeroponics? In Singapore for example this farming approach has a niche.
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Hi John, I'm glad you enjoyed the ACU summer school.
For those that are interested the Association of Commonwealth Universities run an excellent series of summer schools. For more details see the link below:
https://www.acu.ac.uk/news-events/events/commonwealth-summer-school/
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Hi Graham,
You raise an interesting point – should “cash” crops be cultivated instead of dietary staples such as rice when soil conditions are sub-optimal for growth, with the money from their sales used to purchase food? Does anyone have an opinion on this?
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Paul Williams (Educator) made a comment
Could the "System of Rice Intensification (SRI)" be a solution?
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Paul Williams (Educator) made a comment
Could the "System of Rice Intensification (SRI)" be a solution?
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Paul Williams (Educator) made a comment
Iron supplementation has the potential to help many people, however care is also needed.
There is a hereditary condition in which excessive amounts of iron are absorbed from the diet.
Haemochromatosis is especially prevalent among those of Irish & Celtic descent....
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Food fortification is certainly a very viable option.
If you want to know more about the current landscape regarding food fortification in the US – have a look at this article.
http://www.ilsi.org/Pages/ViewItemDetails.aspx?WebId={678CA61D-37F3-4E1D-90DB-E8879920CA55}&ListId={F5A43102-7B6F-4531-A209-AFA2B711282D}&ItemID=229For the Southeast Asian...
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Paul Williams (Educator) made a comment
Another relevant Se paper:
Soil-type influences human selenium status and underlies widespread selenium deficiency risks in Malawi
Nature.. Scientific Reports 3, Article number: 1425 doi:10.1038/srep01425
http://www.nature.com/srep/2013/130312/srep01425/full/srep01425.htmlAbstract: Se is an essential human micronutrient with critical roles in...
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On a related topic does anyone know what the link is between:
• Colocasia esculenta/Taro
• Arsenic
• Iron deficiency -
Hi Martin – excellent question. As far as I’m aware no such map exists. It would be a huge undertaking but potentially also very useful.
Our best guide to country specific trends is still:
Meharg, A. A., Williams, P. N., Deacon, C., Sun, G., Zhu, Y.-G., Feldmann, J., … Hossain, S. (2009). Geographical Variation in Total and Inorganic Arsenic Content of... -
If you’re interested to know more about how we measure inorganic arsenic in rice, then have a look at this free webinar:
“ICP-MS for Arsenic Speciation”
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Paul Williams (Educator) made a comment
http://www.bgs.ac.uk/ebooks/AdvancedSoilGeochemicalAtlasEbook/index.html#/154/
The Advanced Soil Geochemical Atlas of England & Wales - a great resource for those interested in knowing the [Se] in UK soil.
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Paul Williams (Educator) made a comment
New study in Nature Communications finds a potential link between terrestrial selenium distribution in China and monsoonal climate
Nature Communications 5, Article number: 4717 doi:10.1038/ncomms5717
Abstract: The prevalence of terrestrial environments low in the essential trace element Se results in large-scale Se deficiency worldwide. However, the...
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June, thanks for your comments... being based in Malaysia you might be interested in this link:
Tropical Catchment Research Initiative (TROCARI)
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Paul Williams (Educator) made a comment
Should we include the fight against micronutrient deficiencies in the post 2015 global development framework?
http://www.beyond2015.org/content/join-beyond-2015
What about the role played by higher education? Are Universities active enough?
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Paul Williams (Educator) made a comment
If you’re interested to know more about how we measure inorganic arsenic in rice, then have a look at this free webinar:
“ICP-MS for Arsenic Speciation”
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http://pubs.acs.org/doi/abs/10.1021/es400720r
This study looks at arsenic contamination of locally grown fruits & vegetables in Cornwall, Devon & Aberdeenshire.
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Arsenic Speciation and Localization in Horticultural Produce Grown in a Historically Impacted Mining Region
Abstract
A field and market basket study (∼1300 samples) of locally grown fruits and vegetables from historically mined regions of SW England, and as reference, a market basket study of similarly locally grown produce from the NE of Scotland was... -
Dear Ousman, apologises, I'm afraid we have a typo. It should read "oxidant". The sub-section text is being amended as I write.
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Researchers have recently discovered a transporter protein in rice that sequesters arsenic in vacuoles, preventing the toxic element from traveling into grains – could this be the solution we are after?
http://www.the-scientist.com/?articles.view/articleNo/41257/title/How-Rice-Overcomes-Arsenic/
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Could jute mesh be the solution to reducing arsenic loading to paddy fields in Bangladesh?
http://www.scidev.net/south-asia/environment/news/jute-as-arsenic-remover-in-bangladesh.html
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Arsenic testing proposed for geoducks
http://www.kitsapsun.com/news/local-news/environment/arsenic-testing-proposed-for-geoducks
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Here’s an interesting study on inorganic As in mussels.
Sloth & Julshamn, 2008, Journal of Agricultural & Food Chemistry, 54, 4, 1269-1273.
Abstract. The present study reports the findings of unusual high levels of inorganic arsenic in samples of blue mussels A total of 175 pooled samples of blue mussels from various locations along the Norwegian...
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Paul Williams (Educator) made a comment
>New study suggests that optimal selenium status is linked to better mood and less depressive symptoms in young adults.
http://jn.nutrition.org/content/early/2014/11/05/jn.114.198010.abstract>For more information on selenium, why not look at the “International Society for Selenium Research” website:
http://www.seleniumresearch.org/ -
This study (http://edis.ifas.ufl.edu/pi179) highlights that from 1982 to 2007 there has been quite a considerable increase in the expenditure on fungicides in the US, however, if you look at the amount of active ingredient actually deployed then the levels have been steadily falling over this period. Good news for mycorrhizal fungi and a step in the right...
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Paul Williams (Educator) made a comment
I agree mycorrhizal fungi play a huge role in plant-nutrient acquisition – with a few exceptions such as brassicas. Even rice can benefit, see study below from Gao et al. 2007. Plant and Soil, 290:283-291
Abstract
Plant Zn uptake from low Zn soils can be increased by Zn-mobilizing chemical rhizosphere
processes. We studied whether inoculation with... -
Paul Williams (Educator) made a comment
Would improvements to medical diagnostics be a possible solution?
Lab testing reinvented
http://www.tedmed.com/speakers/show?id=308981 -
Fair comment Heather, there is quite a lot of chemistry content. In a short course like this we have to give quite a condensed overview of the topics covered and blend context with content. In the last few sections, we have packed a lot in. However, I still think it is worth it as I hope you can get a flavour of some of the geochemical and biological...
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Can the problem of elevated arsenic in rice be solved just by carefully selecting the right cultivars to grow?
This new study in Southern China.. looks at this question.
Mechanisms Controlling Arsenic Uptake in Rice Grown in Mining Impacted Regions in South China
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0108300(the...
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Johnny, many thanks for posting this link.
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If this topic resonated with you and you want to know more, here are some articles about the Shangba “cancer village” in Guangdong, China.... -
Paul Williams (Educator) made a comment
Consumer Reports advocate a “points value” approach for labelling of rice & rice products – see link below:
http://www.consumerreports.org/cro/magazine/2015/01/how-much-arsenic-is-in-your-rice/index.htm
Could this be the solution?
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Thanks Anne-Marie for your suggestion.. I'll put something together and post it online.
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Paul Williams (Educator) made a comment
If you have a craving for ice.. you might also be iron deficient...
http://www.theguardian.com/science/2014/nov/14/pagophagia-ice-craving-psychology-study -
Paul Williams (Educator) made a comment
Are there any readers from Brazil? I've heard some good things about the "Restaurant Populars" or "People's Restaurants". Could this be a model system to be adopted by other countries to help tackle MN deficiencies in urban settings? Should every country have a national food safety-net?
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I agree.....perhaps we all need to do more to expose policy makers to the risks of inaction? Do you think there has been a general failure for macro-level policy decisions to take micronutrient deficiencies into account? Does anyone have any examples of policies that have had a positive impact?
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Paul Williams (Educator) made a comment
Organic acids such as malate or citrate, and some amino acids such as cysteine & histidine can promote Zn absorption – could these “enhancers” be a viable way to counteract the negative effects of phytate on Zn uptake? Should we be increasing their levels in our foods?
