Mr. Hartan's Science Class
"Knowledge is a reckoning . . . a way to assess your location, your true position, not a strategy for improving your position." -Walter Kirn-Bagged Salad and Fecal Bacteria
March 2010
You might think that “prewashed” and “triple-washed” salad greens sold in plastic clamshells or bags are squeaky clean. But our recent tests found room for improvement.
No, we didn’t find pathogens such as E. coli O157:H7, listeria, or salmonella. With our small sample size—208 containers representing 16 brands purchased at stores in Connecticut, New Jersey, and New York—we didn’t expect to. (The Department of Agriculture, in a test of more than 4,000 samples of loose and packaged salad in 2008, found salmonella in two of them. All of our tests included packaged greens.)
But in our samples, all of which were within their use-by date, we did find bacteria that are common indicators of poor sanitation and fecal contamination—in some cases, at rather high levels.
We tested for total coliforms and for other bacteria, including enterococcus, that are better indicators of fecal contamination. Federal action limits exist for indicator organisms in water, raw meat, milk, and some processed foods, but not produce. Those organisms are typically used to gauge possible pathogen contamination.
Several industry experts we consulted suggested that for leafy greens, an unacceptable level of total coliforms or enterococcus is 10,000 or more colony forming units per gram (CFU/g) or a comparable estimate. In our tests, 39 percent of samples exceeded that level for total coliforms and 23 percent for enterococcus.
Results varied widely among samples, even within the same brand, from undetectable levels of those bacteria to more than 1 million CFU/g. Packages with higher bacteria levels had similarities. Many contained spinach and were one to five days from their use-by date. Packages six to eight days from their use-by date fared better. Whether the greens came in a clamshell or bag, included “baby” greens, or were organic made no difference.
Brands for which we had more than four samples, including national brands Dole, Earthbound Farm Organic, and Fresh Express, plus regional and store brands, had at least one package with relatively high levels of total coliforms or enterococcus. Our tests were conducted at an outside lab over two weeks in August and September with financial support from the Pew Health Group, which is working to improve food safety.
Consumers Union supports Senate Bill 510, the Food Safety Modernization Act, that would, among other things, require the Food and Drug Administration to set stronger produce safety standards. Those should include performance standards for indicators of fecal contamination, such as generic E. coli and enterococcus.
What you can do
- Buy packages as far from their use-by date as you can find.
- Even if the bag says “prewashed” or “triple-washed,” wash the greens yourself. Rinsing won’t remove all bacteria but may remove residual soil.
- Prevent cross contamination by keeping greens away from raw meat. For more information, go to www.ConsumersUnion.org/safefood.
The Forensics Team
Blog Assigment:
What Role Do You Wish to Play on the Forensics Team? Your Response should include the following: Job description, Salary, Education Required, Skills Required, Work Environment, Employment Outlook and references/links. Your response should be clear, concise and accurate.
Background Information:
(Crime Scene Team)
- Paramedic (possibly), First Responding Officers, Lead Investigator and Detectives, Field Evidence Technicians
(Criminalists)
- Latent Print Examiner, Firearms Examiner, Toolmark Examiner, Document Examiner, Trace Evidence Examiner
(Forensics Specialitst)
- Pathologist (Medical Examiner), Anthropologist, Odontologist, Entomologist, Psychiatrist, Serologist, Toxicologist, Botanist, Microbiologist/Cell Biologist.
(Law)
- The Prosecuting or District Attorney.
(Cleanup)
- Crime Scene Cleaners.
(Federal Law Enforcement)
- FBI Agent, ATF Agent, Postal Service (Special Agent), etc.
Remember:
- ENTER ONLY YOUR FIRST NAME, FIRST LETTER OF YOUR LAST NAME AND PERIOD in the appropriate box.
- YOU MUST ENTER AN EMAIL ADDRESS (doesn’t have to be real and only I will see it) in the appropriate box.
- Before submitting your response, please copy it to your clipboard before submitting – just in case anything goes wrong.
US Health Gaps Shame Us All
Courtesy of New Scientist (Opinion)
13 January 2010
HERE is a shaming statistic: divide the US by race, sex and county of residence, and differences in average life expectancy across the various groups can exceed 30 years. The most disadvantaged look like denizens of a poor African country: a boy born on a Native American reservation in Jackson County, South Dakota, for example, will be lucky to reach his 60th birthday. A typical child in Senegal can expect to live longer than that.
America is not alone in this respect. While the picture is less extreme in other rich nations, health inequalities based on race, sex and class exist in most societies – and are only partly explained by access to healthcare.
But fresh insights and solutions may soon be at hand. An innovative project in Chicago to unite sociology and biology is blazing the trail, after discovering that social isolation and fear of crime can help to explain the alarmingly high death rate from breast cancer among the city’s black women. Living in these conditions seems to make tumours more aggressive by changing gene activity, so that cancer cells can use nutrients more effectively (see “Neighbourhoods that can kill”).
We are already familiar with the lethal effect of stress on people clinging to the bottom rungs of the societal ladder, thanks to pioneering studies of British civil servants conducted by Michael Marmot of University College London. What’s exciting about the Chicago project is that it both probes the mechanisms involved in a specific disease and suggests precise remedies. There are drugs that may starve tumours of nutrients and community coordinators could be employed to help reduce social isolation. Encouraged by the US National Institutes of Health, similar projects are springing up to study other pockets of poor health, in populations ranging from urban black men to poor white women in rural Appalachia.
To realise the full potential of such projects, biologists and sociologists will have to start treating one other with a new respect and learn how to collaborate outside their comfort zones. Too many biomedical researchers still take the arrogant view that sociology is a “soft science” with little that’s serious to say about health. And too many sociologists reject any biological angle – fearing that their expertise will be swept aside and that this approach will be used to bolster discredited theories of eugenics, or crude race-based medicine.
It’s time to drop these outdated attitudes and work together for the good of society’s most deprived members. More important, it’s time to use this fusion of biology and sociology to inform public policy. This endeavour has huge implications, not least in cutting the wide health gaps between blacks and whites, rich and poor.
Portland to Get 250ft Vertical Garden with Vegetated Fins
Portland to Get 250ft Vertical Garden with Vegetated Fins
by Ariel Schwartz, 01/19/10
Vertical gardens are nothing new — avid readers of Inhabitat may even remember PNC Bank’s announcement that it completed North America’s largest living wall back in September — but the garden currently being planned for a Portland, Oregon high-rise is one of the most unique we’ve seen. A series of 250 foot tall trellises will shade the west side of the 18-story Wyatt Federal Building, which is undergoing a $135 million green remodel by SERA Architects courtesy of federal stimulus funds. 
Unlike in traditional vertical gardens, the Wyatt Federal Building will feature a series of seven so-called “vegetated fins” will jut out from the building as a framework for planters.
There are a number of advantages to building the garden on the 150 foot long west wall of the building — cooling and shade for the building, eye candy for the crowds below, and the light admitted into the building during the winter by bare stems and leaves. But many kinks have yet to be worked out, including how to water, weed, and fertilize crops located 200 feet in the air.
The vertical garden isn’t the only new feature for the high-rise. Other improvements include solar arrays, a smart lighting system, and electricity-generating elevators.
Instant Expert: Forensic Science
Instant Expert: Forensic Science on 10 November 2006 by John Pickrell
Forensic officers at the scene of a suspicious death (Image: Albanpix Ltd/Rex Features)
Forensic science has become a hot subject due to US television shows such as CSI: Crime Scene Investigation and Law and Order. Forensics university courses have proliferated as students flock to this glamorous and exciting scientific discipline.
The reality may be more mundane, but forensic scientists do invaluable work linking evidence from crime scenes – such as fingerprints, injuries, weapons, DNA, computer data, drugs and counterfeit goods – to criminals themselves. Forensic scientists also help solve crimes by reconstructing faces from skulls, and sometimes animating or virtually ageing them, or studying corpses to pinpoint the cause and time of death.
Criminals almost always leave evidence at crime scenes, or unwittingly collected it. Our ability to detect this evidence is continually improving, and many court cases rely it. It is presented to juries and judges by expert witnesses and helps solve crimes from fraud and forgery to assault, rape, murder and terrorism. Forensics can even help uncover secret nuclear weapons programs, smuggled plutonium and thwart trafficking of drugs and endangered species.
CSI New Scientist: Test your bloodstain analysis skills
CSI NEW SCIENTIST: TEST YOUR BLOODSTAIN ANALYSIS SKILLS
- 14:25 25 February 2009 by Linda Geddes
- For similar stories, visit the Galleries , Crime and Forensics and Death Topic Guides
Test your ability to identify bloodstains with our quiz
Bloodstain analysts claim to be able to identify how a bloodstain was created – whether by dragging, dripping, or impact at close range – simply by looking at it. But no-one has tested the accuracy with which they can do this until now.
Brian Gestring of Cedar Crest College in Allentown, Pennsylvania, conducted a preliminary study in which 92 professional analysts and 65 non-experts were asked to name the mechanism by which ten different blood patterns were created. The blood patterns were not from real crime scenes, but were recreated using animal blood.
He found that the experts got it right 97% of the time, while laypeople guessed correctly in 21% of cases. The study, which was presented at a meeting of the American Academy of Forensic Sciences in Denver, Colorado, last week, is a first step towards being able to quantify an error rate for bloodstain analysis. Jurors could be presented with the error rates when hearing evidence in court.
The next step will be to recreate an entire crime scene and test the ability of analysts to interpret what has happened.
Forensic Science Goes on Trial
New Scientist on 25 February 2009 by Linda Geddes
FORENSIC SCIENCE GOES ON TRIAL
(New Scientist - Image: Peter Menzal/SPL)
LAST month, Steven Barnes was exonerated of the rape and murder of a 16-year-old New York schoolgirl in 1985. Barnes had been convicted of these crimes on the basis of forensic evidence, including testimony that soil on his truck tyres matched that at the crime scene. An imprint on the outside of his truck also supposedly matched the pattern of the jeans the victim was wearing when she was killed. But this year, tests showed that DNA samples from the murdered girl’s body and clothing did not match Barnes’s, and he was freed after spending 20 years in jail.
The US National Academy of Sciences fears that miscarriages of justice like Barnes’s original conviction are all too common. In a highly critical report on the state of forensic science in the US, published last week, it questions the reliability of using techniques like hair or fingerprint analysis to link a person to a crime. READ ON.
Stiff: The Curious Lives of Human Cadavers
Stiff: The Curious Lives of Human Cadavers by Mary Roach
INSTRUCTIONS:
- You are to read Chapter 3 of the above book (Life After Death: On Human Decay and What Can be Done About It).
- You are going to respond to this chapter as a blog entry. Click HERE to go to the response page. Please make sure you put your first name and the initial of your last name/period. For example, ‘John S3.’
ASSIGNMENT:
- Your blog response should consists of 3 paragraphs. There must be evidence that you have read Chapter 3.
- The first paragraph should be a summary of the article. The second paragraph should be a list of 10 things you found interesting about the chapter. The third paragraph should be your reaction (thoughts, emotions, likes/dislikes, recommendations) with regard to the chapter.
