Category Archives: water

Arsenic in Rice and Long-Term Health Risks

Arsenic in rice has been reported as being of no immediate health risk.  But the major concern with arsenic is that it is a long-term health risk.  Arsenic may be best known as a tool of poisoners.  But arsenic poses greater risk as a slow, quiet inducer of cancer.  In that way, arsenic is like most carcinogens.  The problem is not that someone would eat a bite of rice and then fall face first into his or her plate.  The problem is that arsenic causes skin and bladder cancer.  It also does other unpleasant things to people who are exposed to relatively low levels over long periods of time.

Arsenic in Rice and Arsenic in Drinking Water

Arsenic in rice and drinking water
Arsenic in rice may add to cancer risk.  Photo by Reuters

The current limit for arsenic in drinking water is 10 parts arsenic for every billion parts of water.  If you are an average adult drinking two liters of water you could get about 20 micrograms of arsenic.  As long as your drinking water meets federal standards.  If you drink more than two liters of water your will probably be just fine.  If you get more than 20 micrograms of arsenic every day you will probably be fine too.  Federal standards have built in safety factors.  These protect people who are not average 160 pound adults. Who drink two liters of water a day.  If people are exposed to additional arsenic in rice on a regular basis in addition to arsenic in water they may face increased risk of cancer.  The man in the photo on the right lives in an area where arsenic in drinking water greatly exceeds World Health Organization standards.

Should I worry about Arsenic in Rice?

Maybe.  Arsenic in rice may increase your risk of cancer.  Especially if you live in an area where arsenic levels in drinking water are high.   Or if you are feeding rice to infants or very young children.   Infants and young children tend to rely on only a few types of food.  If you are a heavy rice eater you should add some other grains to your diet.  The best way to protect yourself from contaminants in food is to eat a varied diet.  And not depend too heavily on any one food type.  To find out if you live in an area where arsenic in drinking water is a high take a look at the map below.  Keep in mind that if you live in a high-arsenic area your community drinking water may be less if it is treated.   If you live outside the US you can probably find a map for your country online.  Keep in mind too that arsenic levels in rice will vary.  The amount of arsenic in rice will depend on how much arsenic was in the ground and water at the growing site.

Arsenic in Rice Arsenic in Drinking water
USGS Map of Arsenic Concentrations in drinking water.


Estrogen and Progesterone in Waterways

In the last post, I was speculating about how estrogens from effluent might end up in way water ways and end up increasing the incidence of prostate cancer. I wondered if the problem (if it there is anything more than a chance association) might be progesterone from birth control pills rather than estrogen. Progesterone is markedly non-soluble in water so it seemed unlikely at first thought. Poking around a little, progesterone might end up in sewage effluent after all. The three studies below report on fecal and/or urinary progesterone, conjugated progesterone or “progesterone metabolites” in animals. So . . . maybe progesterone contamination of water might be relevant. And, not all sewage is filtered and treated. I recently watched someone emptying a truckload of portapotties into one of our local creeks. (Yes, I called the police, who told me it was not their problem.) Don’t know if anyone has looked at this or not. If you know, please have at it in comments.

deCatanzaro D, Muir C, Beaton EA, & Jetha M (2004). Non-invasive repeated measurement of urinary progesterone, 17beta-estradiol, and testosterone in developing, cycling, pregnant, and postpartum female mice. Steroids, 69 (10), 687-96 PMID: 15465115Kinoshita K, Inada S, Seki K, Sasaki A, Hama N, & Kusunoki H (2011). Long-term monitoring of fecal steroid hormones in female snow leopards (Panthera uncia) during pregnancy or pseudopregnancy. PloS one, 6 (5) PMID: 21559303Brown JL, Wasser SK, Wildt DE, & Graham LH (1994). Comparative aspects of steroid hormone metabolism and ovarian activity in felids, measured noninvasively in feces. Biology of reproduction, 51 (4), 776-86 PMID: 7819459google-site-verification: googleaa234ad89e44d776.html