Blog

A public health nurse is evaluating a new screening program for type 2 diabetes that uses a blood test with high sensitivity but only moderate specificity. The program identifies a large number of individuals as “positive,” but follow-up diagnostic testing reveals that many of them do not actually have diabetes. Which interpretation by the nurse best reflects an understanding of the test’s screening characteristics?

A community health nurse is developing a program to reduce the incidence of breast cancer–related mortality in a county with high rates of late-stage diagnosis. Which planned activity best demonstrates the use of secondary prevention for this public health problem?

In the reading by Meyers (The Rise of the Precautionary Principle), the author claims

The table below lists the lethal dose (LD50) values for various compounds. Based on these numbers, which compound is the MOST toxic by weight? Compound Found in LD50 Acetylsalicylic acid Aspirin 200 mg/kg Chlorine (CI2) fumes Bleach 850 mg/kg Caffeine Coffee 140 mg/kg Ethanol Alcoholic drinks 7060 mg/kg Gyromitrin Mushrooms 200 mg/kg

In class we discussed the increase in cases of microcephaly in babies born in Brazil in 2015. Some individuals thought this increase was due to a mosquito borne disease called Zika. Others were concerned that a mosquito larvicide (Pyriproxyfen) was responsible for the increased microcephaly. In this case the statement that Pyriproxyfen causes microcephaly is a [ans1].  To try to get at the answer for what is causing the increased cases of microcephaly, scientists have looked regionally at the frequency of microcephaly cases and frequency of the larvicide use, with the idea that if there were a positive relationship between the two, that would give [ans2] . Scientists have also done controlled laboratory studies in which they have exposed laboratory animals to the Zika virus and found those exposed to the virus during pregnancy had offspring with a higher incidence of microcephaly, suggesting a [ans3] between the zika virus and the microcephaly condition in the laboratory animals.

From a scientific and toxicological standpoint, how should we determine what toxicants to worry about?

Pesticides like atrazine in the United States are registered through the _______________.

The table below contains information for various insecticides LD50s of various pesticides Chemical Synthetic/natural Oral LD50 in rats (mg/kg) Dieldrin Synthetic 40 Malathion Synthetic 885 Rotenone Natural (plant extract) 60 Pyrethrins Natural (plant extract) 200 With regard to oral toxicity in rats, from this table we can conclude:

A toxicologist is studying population of a small minnow that live in a pond near an industrial site that uses and discharges a variety of chemicals. They notice that an unusually high proportion of the minnows have tumors on their livers. Why might this be of concern? I. The minnows are important members of an ecosystem – if something is affecting their health it might impact the stability of the whole ecosystem. II. If the compounds that are making their way into the pond they may be making their way into other materials to which humans are exposed (air, well water, soil). The effect on fish might be an early warning for potential impacts on humans. III. There is no reason to be concerned about this, because fish and humans are very different. IV. There would only be reason to worry if this were happening in walleye or bass (fish humans eat).

The figure below shows the effects of nicotine and chlorpyrifos on brain development. From these data we can conclude: