Arsenic Poisoning

Arsenic is a common natural and anthropogenic contaminant in sediments, surface waters, and ground waters. In Taiwan, Bangladesh, and the United States arsenic poisoning has been linked to disorders such as hyperpigmentation (Black-foot disease), Peripheral Vascular Disease, skin and bladder cancer, and gangrene ^2,3. Sporadic occurrences of Black-foot disease occurred in southwest Taiwan in the early twentieth century with a peak incidence in the late fifty’s ². The cause of this arsenic poisoning was due to resident’s use of contaminated artesian wells ². Arsenic poisoning incidents reduced significantly when residents began switching to tap water in the endemic villages ². Awareness of this outbreak caused the EPA cancer risk assessment to use the cancer data from Southwest Taiwan to predict the cancer risk assessment in the United States ^4,6. Recently changes in water quality standards in America along with greater understanding of arsenic toxicity have increased the necessity for methods of determining potentially bioavailable arsenic in field environments as well as characterization in natural environments.

Complex geochemical and biological mechanisms control the distribution of arsenic within repositories in the biosphere, hydrosphere, and lithosphere. Arsenic in water is primarily found in two oxidation states, As (III) and As (V) ¹. As (III) is considered more toxic than As (V), and is generally less mobile. Therefore, under many conditions As sequestion is undergone through reduction. This, however, is problematic because reducing environments release arsenic from arsenic bearing minerals such as oxyhydroxides. This is exactly what happened in Bangladesh when buried deposits of peat acted as electron donors for the reduction of arsenic bearing Goethite into the groundwaters^3. Controls on the distribution of arsenic include: redox conditions, pH, presence of Iron and Manganese Oxyhydroxides, and metabolic activities of microorganisms. Iron oxides, however, generally control arsenic speciation in near-surface environments ¹. Iron, when present, in the environment, controls the mobility, fate, and bioavailability of aqueous arsenic species by converting bioavailable arsenite (AsO₃^3-) and arsenate (AsO₄^3-) species to immobilized forms adsorbed or coprecipitated in iron oxides ¹. Chemical availability of As is an indirect measure of bioavailability. Bioavailability refers to the concentration of a target chemical that actually enters the systemic circulation of an organism from an administered dose⁵. (commonly considered the total concentration of the chemical present in the organism’s environment). It is generally assumed that dissolved phases are most bioavailable ⁵. Chemical availability of As is dependent on speciation. Therefore, when the speciation of arsenic in a soil system is known the chemical availability becomes a good indicator of bioavailability.

The World Health Organization estimates that 41 million people worldwide (some sources estimate 57 million) are drinking groundwater contaminated by arsenic at unsafe levels ¹⁰. In Taiwan alone approximately 2 million people are potentially exposed to polluted water ⁹. Arsenic, although rare in natural abundance in the lithosphere, is common in sulfides such as chalcopyrite, realgar, orpiment, galena, marcasite, arsenopyrite, enargite, and it has a strong affinity for pyrite, one of the world’s most common minerals ⁹. It is also common in other minerals through substitution. Arsenic in groundwater is often the result of dissolving weathered rock and soils or through reduction of iron oxides. In the case of the massive epidemic in Bangladesh the arsenic is released to the groundwater through goethite (FeOOH) reduction ⁴. Which is driven by microbial degradation of buried deposits of peat. The peat acts as an electron donor so that iron oxide reduction can take place.

Arsenic is often added to groundwater through anthropogenic sources such as use in alloying agents, wood preservatives, mineral extraction and processing wastes, poultry and swine feed additives, pesticides, and highly soluble arsenic trioxide stockpiles ^1,9. The most globally significant anthropomorphic source of arsenic is probably through combustion of fossil fuels ¹². The arsenic mainly appears as arsenite in the dust and travels through the atmosphere releasing arsenic throughout the globe. In 1988 Nriagu and Pacyna estimated that as much 70% of the global atmospheric As flux is anthropogenic. In the past arsenic acid was even used as a cotton defoliant in the southern part of the United States ¹¹.

Globally, millions of people are at risk for the adverse effects of arsenic exposure. Contaminated drinking water is usually contaminated through inorganic arsenic. Inorganic arsenic is more acutely toxic that organic arsenic species ^2,3. Other countries than Taiwan and Bangladesh that currently face arsenic exposure include: Argentina, Cambodia, Chile, China, Ghana, Hungary, India, Mexico, Vietnam, Tibet, Thailand, as well as the United States ^1,2,3,9. As the world population increases beyond 6 billion clean drinking water is quickly becoming one of globe’s most valuable resources. In order to protect our drinking water we must continue to study and understand contaminants of all varieties. This is a fundamental mission and goal of the applicant’s research group at Texas A&M University. This project will directly aid in this endeavor. Additionally, the international component to the proposed research will serve as a reminder to the scientific community of the importance in scientific collaboration and goodwill across global borders in solving the world’s environmental issues.

 This post is an excerpt from a copywritten article written by Clint Miller. All quotes must be cited to me.

Evaluating Arsenic Availability in Taiwanese Soils using DOWEX M4195, Fe³⁺ Substituted, Resin; Clint Miller; NSF EAPSI Grant Application; 2007

References

1. A review of the source, behaviour and distribution of arsenic in natural waters; P.L. Smedley*, D.G. Kinniburgh, Applied Geochemistry 17 (2002) 517-568

2. Long-term arsenic exposure and ischemic heart disease in arseniasis-hyperendemic villages in Taiwan, Chin-Hsiao Tseng, Choon-Khim Chong, Ching-Ping Tseng, Yu-Mei Hsueh, Hung-Yi Chiou, Ching-Chung Tseng, and Chien-Jen Chen; Toxicology Letters, Volume 137, Issues 1-2, 31 January 2003, Pages 15-21

3. Arsenic poisoning in groundwater: Health risk and geochemical sources in Bangladesh, H. M. Anawar, J. Akai, K. M. G. Mostofa, S. Safiullah, and S. M. Tareq; Environment International, Volume 27, Issue 7, February 2002, Pages 597-604

4. Significance of Exposure Assessment to Analysis of Cancer Risk from Inorganic Arsenic in Drinking Water in Taiwan; Kenneth G. Brown and Chien-Jen Chen; Risk Analysis, Volume 15 Issue 4 Page 475-484, August 1995

5. An In Vitro Gastrointestinal Method To Estimate Bioavailable Arsenic in Contaminated Soils and Solid Media; Rodriguez, R. R.; Basta, N. T.; Casteel, S.; S. W.; Pace, L. W.; Environmental Science & Technology, 1999, 33, 642-649

6. Inorganic arsenic: a need and an opportunity to improve risk assessment; W R Chappell, B D Beck, K G Brown, R Chaney, R Cothern, C R Cothern, K J Irgolic, D W North, I Thornton, and T A Tsongas; Environ Health Perspect. 1997 October; 105(10): 1060-1067.

7. Quantification of Potential Arsenic Bioavailability in Spatially Varying Geologic Environments at the Watershed Scale using Chelating Resins; Lake, G. E.; M.A. Thesis, Texas A&M University, 2002), 227 pp

8. Assessment of the phytotoxicity of chromium in soils using the selective ion exchange resin extraction method; Pei-Fang Yu, Kai-Wei Juang and Dar-Yuan Lee; Plant and Soil 258: 333-340, 2004.

9. Contamination of drinking-water by arsenic in Bangladesh: a public health emergency; Allan H. Smith; Elena O. Lingas; Mahfuzar Rahman; Bulletin of the World Health Organization; Print ISSN 0042-9686; Bull World Health Organ vol. 78 no. 9 Genebra 2000

10. Worldwide Occurrences of Arsenic in Ground Water; D. Kirk Nordstrom, SCIENCE VOL 296, 21 JUNE 2002; 2143-2145

11. Occurrence and Distribution of Arsenic in Soils and Plants; Leo M. Walsh; Malcolm E. Sumner; Dennis R. Keeney; Environmental Health Perspectives, Vol. 19. (Aug., 1977), pp. 67-71

12. Quantitative assessment of worldwide contamination of air, water, and soils by trace metals; Nriagu, J.O., Pacyna, J.M., Nature 333, 134-139; 1988

Endocrine Disrupting Compounds: 2. Bisphenolic Compounds

Bisphenolic Compounds are used in the synthesis of polycarbonate plastic and epoxy resins for many companies. Recently, Bisphenol-A (BPA) has received much attention in the news media after being reported to leach from baby bottles after heating in the microwave. BPA has also been reported to leach from other products such as: the plastic lining of cans used for food, tableware, and white dental fillings and sealants. Bisphenol-A is an endocrine disrupting compound that has been found to promote many deleterious health effects. BPA mimics the female hormone, oestrogen, disrupts the chemical communication system within the cells of the body^1,2.

1. Determination of Endocrine-Disrupting Phenolic Compounds and Estrogens in Surface and Drinking Water by HRGC-(NCI)-MS in the Picogram per Liter Range; Holger M. Kuch and Karlheinz Ballschmiter; Environ. Sci. Technol., 35 (15), 3201 -3206,
2001

2. Large effects from small exposures. I. Mechanisms for endocrine-disrupting chemicals with estrogenic activity; Wade V Welshons, Kristina A Thayer, Barbara M Judy, Julia A Taylor, Edward M Curran, and Frederick S vom Saal; Environ Health Perspect. 2003 June; 111(8): 994-1006.

3. Simultaneous determination of endocrine disrupting phenolic compounds and steroids in water by solid-phase extraction-gas chromatography-mass spectrometry; R. Liu, J. L. Zhou and A. Wilding; Journal of Chromatography A ; Volume 1022, Issues 1-2, 2 January 2004, Pages 179-189  

Endocrine Disrupting Compounds: 1. Alkylphenolic Compounds

Alkylphenolic compounds are non-ionic surfactants used as cleaning agents that have been identified as Endocrine Disrupting Compounds. They can also enhance defoaming, deemulsification, dispersion, and solubilization of other products¹. The original compounds are not considered highly toxic, but their metabolic derivatives can be highly recalcitrant¹and endocrine disrupting⁴. Alkylphenolic compounds can be estrogenic to fish and mammals⁴.

Some types of Alkylphenolic Compounds include: Nonylphenol, Pentylphenol, octylphenol, nonylphenol mono and diethoxylates.

1. Analysis and environmental levels of endocrine disrupting compounds in freshwater sediments; Mira Petrovicè, Ethel Eljarrat, Maria J. Loèpez de Alda, Damiaé Barceloè; trends in analytical chemistry, vol. 20, no. 11, 2001

2. Distribution and Fate of Neutral Alkylphenol Ethoxylate Metabolites in a Sewage-Impacted Urban Estuary; P. Lee Ferguson, Charles R. Iden, and Bruce J. Brownawell; Environ. Sci. Technol., 35 (12), 2428 -2435,
2001.

3. 4-Nonylphenol in sewage sludge: accumulation of toxic metabolites from nonionic surfactants; W Giger, PH Brunner, and C Schaffner; Science, Vol 225, Issue 4662, 623-625

4. Environmentally persistent alkylphenolic compounds are estrogenic; R. White, S Jobling, SA Hoare, JP Sumpter, and MG Parker; Endocrinology, Vol. 135, 175-182

I got my research grant!

I received notification yesterday that the National Science Foundation has approved my application for the East Asia and Pacific Summer Institutes Program! My full acceptance is pending my host institution’s (National Taiwan University) approval, but since I have been in contact with them from the beginning and they have already expressed interest I expect no problems.

 The financial reward is $5000. I will be traveling to Taiwan this summer for 7 weeks. The research I proposed was in-situ measurement of Arsenic in Taiwan’s soils. Arsenic is a major contaminant in soils around the world, and is controlled by speciation (Arsenate and Arsenite).

 I am super excited!!!!! 

Endocrine Disrupting Compounds; Bisphenol-A, Phthalate Esters, Dioxins, and lots of others

One hot topic you may hear about in Environmental Science and Toxicology are Endocrine Disrupting Compounds. They have been all over the news in the last 10 to 15 years. You might have heard about fish and guppies spontaneously changing sex or baby bottles releasing chemicals after being heated in the microwave. These are two examples of Endocrine Disrupting Compounds (EDCs).

Endocrine systems of animals and humans are very complex, and rely on the ability to send and receive ‘messages’ in the form of hormones inside cells. When part of a cell sends a message in the form of a hormone to another part of the cell it is called the messenger. The portion that receives the information is called the receptor. This message tells the cell to perform a specific biological task such as growth or reproduction or embryonic development⁴.

An Endocrine Disrupting Compound is therefore a compound that interferes with the communication. Some compounds can mimic hormones and therefore produce normal but untimely responses. Others are antagonistic and disrupt the normal functions by binding to the receptor thus blocking other messages or by interfering with the way hormones are made and controlled.

EDCs are very controversial within the scientific community. It is not controversial that certain organic compounds can disrupt the endocrine messaging process, but there is great controversy as to whether the dose/response relationship of tests accurately models real life. Let me explain. In the lab scientists often spike samples with high doses to see the results. In the environment animals are almost never subjected to very high concentrations^7.8. This leads to the question of whether EDCs can be additive with time (i.e. low dose long time=high dose short time) or whether different EDCs can be synergistic (i.e. work together).

There are many different types of EDCs around. Here is a table of some of the most well known.

Some Endocrine Disrupting Compounds
Category	Name	Some Sources
Alkylphenols (Surfactants)	Nonylphenol, Pentylphenol, octylphenol, nonylphenol mono and diethoxylates	Industrial and municipal effluents
Bisphenolic Compounds	Bisphenol A	Used in the synthesis of polycarbonate plastic and epoxy resins
Natural Hormones/ Synthetic Steroids	17-b-estradiol, estrone, Testosterone; ethynyl estradiol	Municipal effluent and agricultural runoff
Organochlorine Pesticides	DDT, dieldrin , lindane	Agricultural runoff, Atmospheric transport
Organotins	Tributyltin	Shipping Harbors; Used in: Wood Preservative, Antibiofouling Agents
Pesticides	Atrazine, trifluralin, permethrin	Agricultural runoff
Phthalates	Dibutyl phthalate, butylbenzyl phthalate, phthalate esters	Industrial effluent
Phytoestrogens	Isoflavones, ligans, coumestans	Pulp mill effluents
Polybrominated Compounds	Polybrominated diphenyl ethers	Flame retardants
Polychlorinated Compounds	Polychlorinated dioxins, polychlorinated biphenyls	Landfills Used in: Coolants, Insulating Fluids, PVC Pipes, Flame Retardents, etc.

Source 4,6

That is all I will write about Endocrine Disrupting Compounds in this post. I will try to write descriptions of each of these soon. Look for links.

1. Bisphenol-A: an estrogenic substance is released from polycarbonate flasks during autoclaving; AV Krishnan, P Stathis, SF Permuth, L Tokes and D Feldman; Endocrinology, Vol 132, 2279-2286, Copyright © 1993 by Endocrine Society

2. Relative binding affinity-serum modified access (RBA-SMA) assay predicts the relative in vivo bioactivity of the xenoestrogens bisphenol A and octylphenol; S C Nagel, F S vom Saal, K A Thayer, M G Dhar, M Boechler, and W V Welshons; Environ Health Perspect. 1997 January; 105(1): 70-76.

3. A physiologically based approach to the study of bisphenol A and other estrogenic chemicals on the size of reproductive organs, daily sperm production, and behavior; vom Saal FS, Cooke PS, Buchanan DL, Palanza P, Thayer KA, Nagel SC, Parmigiani S, Welshons WV.; Toxicol Ind Health. 1998 Jan-Apr;14(1-2):239-60

4. Endocrine Disrupting Substances in the Environment; Environment Canada; http://www.ec.gc.ca/eds/fact/broch_e.htm

5. Phthalates, Alkylphenols, Pesticides, Polybrominated Diphenyl Ethers, and Other Endocrine Disrupting Compounds in Indoor Air and Dust; Ruthann A. Rudel, David E. Camann, John D. Spengler, Leo R. Korn, Julia G. Brody; Environmental Science & Technology

6. Analysis and environmental levels of endocrine-disrupting compounds in freshwater sediments; Mira Petrovi , Ethel Eljarrat, Maria J. López de Alda and Damià Barceló; Copyright © 2001 Elsevier Science B.V.

7. Endocrine disruptors and reproductive development: a weight-of-evidence overview; RL Cooper and RJ Kavlock; Journal of Endocrinology, Vol 152, Issue 2, 159-166

8. Endocrine Disruptors and Human Health-is there a problem? An update.; Stephen H Safe; Environmental Health Perspectives, Vol. 108, Number 6, June 2000

Christian service, environmental science, and a burp that wouldn’t burp part 2.

 Part 2. Christian Service

Recently I have been really convicted of several things that I consider central to Christianity, but have basically no part in my life now that I am in grad school. I have realized that I have become a hypocrite about these things because I proclaim them, but I never do them. Here are some examples:

• Giving to the poor
• Taking care of the widows/elderly
• Mourning with those who mourn
• Hurting with those who are hurting
• Being merciful
• Loving everyone…UNCONDITIONALLY
• Hundreds of other ways to serve

I was mentioning these to an older man in the church that is discipling me, and he suddenly became quiet and looked contemplative. I asked him what he was thinking, and he mentioned that he was trying to figure out why his first thought was, “Well, we can’t do everything.” I immediately caught his drift. This is exactly what I use to convince myself that I don’t need to be serving others right now.

My schedule is crazy. I know that every college student says this, but I mean it. Here is my normal day.

I get up at 5:30 and spend time with Christ for about an hourish.

7:00 I get ready and eat breakfast

8:00ish I arrive at school and do homework in my office

11:00 Go to class and then eat

1:00 Work in the lab on projects

2:00 Go to class again

4 or 5:00 Go back to the lab or study

7 or 8 Go home and Eat dinner

10 or 11 Go to bed

That isn’t including bible studies or things like that some evenings. Usually I am sprinting from one thing to another. I am constantly late for class. I am not complaining. This is what grad school is. I knew that going into it. But I am starting to realize. If I am so busy that I don’t have time to serve others then what is the point?

One of my friends has clinical depression and has tried to commit suicide 3 times. Most recently she tried to cut her wrists before Christmas. She doesn’t live in America, but I see her online fairly often. If I don’t sit down and encourage her and listen to her then who will? Seriously, is she not worth me doing slightly worse on my next test?

I was talking to one of my friends yesterday. He was telling me that he and his roommates have started really spending a lot of time with their neighbors. They invite them over and hang out. They play with them. Take care of their kids (one has an autistic child) to give them a break. They even just started having a weekly dinner where they have a bible study before the meal. That brothers—you know if I am talking about you— is super encouraging. You are getting it right, and Jesus is shinning through you.

God seems to be answering my prayers also. I just joined a home group from church. I assumed it would be a bunch of older people with kids who like to sit around, it is totally not. Right off the bat they started talking about all the ways that we can serve others as a group. They have all these ideas. It was crazy. One of the couples has like 700 adopted kids in their house. One other lady is bringing a small orphan girl from Middle America to live with her for a couple months so she can get a medical examination and a hearing aid. That is doing it right. I mentioned that International Students at A&M tend to be very lonely and isolated. They immediately were asking for ideas on how they could serve the international students. I was blown back.

Thank you Jesus for putting people like this in my life.

Christian service, environmental science, and a burp that wouldn’t burp part 1.

 Part 1. A Burp that wouldn’t burp

The last two weeks of my life have really sucked and yet…well, they have been awesome at the same time. It seems like life is usually like that. We get the ups and we get the downs, but somehow the ups seem to be connected more with their downs than with other ups and the downs seem to be one the causes of the ups rather than the absence of ups. Got that?

I have had really good times with the Lord this week though, and the reason is because I have been brought to my knees. I have always struggled with anxiety you see, and these past two weeks have been a real knock down brawl street fight biting scratching spiting thing.

It started out with something I tried the Monday before last that kicked my butt. I woke up at like 3:00 in the morning the next day worrying like crazy. It didn’t even make sense type of worry. It was totally irrational. I talked to several people and they were like, “Dude that totally doesn’t make any sense.” Ok, maybe they didn’t say dude in real life, but they do in my memory. I knew it didn’t, but I couldn’t convince myself to let it go. It was there always…like a burp that wont burp. It just stays in your chest. Making you feel motion sick.

After a few days of feeling like total crap my roommate, Chris, pointed out to me in 2 Corinthians the difference between Godly sorrow and worldly sorrow. My sorrow fell completely under the description of worldly sorrow. Then, I was able to talk to my college pastor about it. He actually struggled to understand what I was saying. I bet he has heard like 500 whiny college students explain their struggles. He has known me since 2001, and he still struggled to understand me. What does that tell you?

I guess that is how it is when you struggle with anxiety. It is yours and no one else’s. You own it. You selfishly take it and nurture it until it is a full blown anxiety. My college pastor did figure it out (Actually I already knew all about it, but I needed somebody I trusted to say the same thing before I explained it), and he pointed out the parts that were legitimate fears that I could take to Christ and the parts that had gotten jumbled in with the rest. He pointed out that the enemy likes to keep things jumbled, general, and fear filled whereas Christ brings clarity, specificity, and hope.

That night I prayed before I went to bed that Christ would protect me from my daily ritual of waking up at 3:00 AM and sitting in bed worrying for 3 hours until it was time for school. Well, I still woke up, but I immediately opened up my bible and started having my quiet time with the Lord. He then took me to this passage. Check it out.

Tremble, and do not sin;

Meditate in your heart upon your bed, and be still.

Selah. 

Offer the sacrifices of righteousness,

And trust in the LORD.

Many are saying, “Who will show us good?”

Lift up the light of Your countenance upon us, O LORD! 

You have put gladness in my heart,

More than when their grain and new wine abound. 

In peace I will both lie down and sleep,

For You alone, O LORD, make me to dwell in safety.

Psalm 4: 4-8

Wow, that had to be one of the most obvious answers to prayer I have ever experienced! I mean seriously…tremble…but don’t sin. I was trembling. Meditate in your heart upon your bed, and be still. Where do you think I was sitting? In peace I will both lie down and sleep, for You alone, O Lord, make me dwell in safety. For the rest of this week I have gotten up early to have my time with the Lord. I still struggle with anxietal residue, but I am learning that I need the Lord every single day. He gives peace freely. Just ask.

Part 2, “Serving Others” coming soon.

Ann Coulter votes for….Hillary Clinton?

Ann Coulter author of, “If Democrats had any brains” spoke out on Hannity and Colmes saying that if John McCain wins the Republican nomination then she will campaign for Hillary Clinton. Ann Coulter the uber conservative of television came out to say that she believes Hillary Clinton is stronger on national defense and is actually less liberal than John McCain on several issues. Personally, I think that she is just angry that any Republican would have the audacity to work across the aisle on legislation. Here is the video. What do you guys think?