The impact of triclosan, an antibacterial agent commonly added to consumer products, on microbial populations in soil irrigated with waste water from households was examined. It was found that irrigation of soil with triclosan containing waste water results in both an increase in resistant bacteria and a concomitant decrease in overall microbial community diversity. These changes in the soil microbiota raise public health and environmental concerns about the release of untreated household waste streams into terrestrial ecosystems. Before irrigation with waste water can become a useful water reuse alternative, additional research focusing on the long-term impacts of triclosan and other pharmaceuticals and personal care products is needed.



18. The passage provides information on each of the following except

A) whether soil irrigation with triclosan-containing waste water affects how many different types of bacteria will be found in that soil
A decrease in community diversity in the soil means there will be less types of microbes found in any soil irrigated with triclosan containing waste water. Bacteria are both microbes and members of the microbial community. So how many types? Not many types.

B) the origin of the triclosan detected in the soil samples studied.
It was from consumer products used in households.

C) whether irrigation with waste water is a viable idea
see Official Explanation

D) what changes soil microbiota undergo when exposed to triclosan
There will be an increase in triclosan-resistant bacteria and a decrease in diversity within the soil microbiome

E) the reasoning for introducing waste water into the ecosystem studied
To resuse it for the purpose of irrigation

hey Carcass
Which of the following statements is supported by the passage?

A) In soil irrigated with triclosan-containing waste water, the overall number of bacteria decreased.
it was found that irrigation of soil with triclosan containing waste water results in both an increase in resistant bacteria and a concomitant decrease in overall microbial community diversity.

if their is increase in resistant bacteria then we can asses that bacteria will go down right ?

The impact of triclosan, an antibacterial agent commonly added to consumer products, on microbial populations in soil irrigated with waste water from households was examined.

Ok. We want see what happens when triclosan goes into the soil

It was found that irrigation of soil with triclosan containing waste water results in both an increase in [b]resistant bacteria and a concomitant decrease in overall microbial community diversity. [/b]

Ok. These are the effects

These changes in the soil microbiota raise public health and environmental concerns about the release of untreated household waste streams into terrestrial ecosystems.

Triclosa + waste water not properly treated impacts the around ecosystem


Before irrigation with waste water can become a useful water reuse alternative, additional research focusing on the long-term impacts of triclosan and other pharmaceuticals and personal care products is needed.

Before to irrigate with waste water we should study this practice more

Which of the following statements is supported by the passage?

A) In soil irrigated with triclosan-containing waste water, the overall number of bacteria decreased.

The good bacteria and microbiota decrease . NOT the overall bacteria

B) The use of triclosan should be curtailed whenever possible due to its environmental impact.


It has impact but nothing is suggested to curtail

C) Bacteria that develop a resistance to anti-bacterial drugs are of more concern than bacteria that have not developed such a resistance.

Ytue because is the only left notion we have. Not sure it is 100% infer.

Not a great passage

The passage provides information on each of the following except

A) whether soil irrigation with triclosan-containing waste water affects how many different types of bacteria will be found in that soil
B) the origin of the triclosan detected in the soil samples studied
C) whether irrigation with waste water is a viable idea
D) what changes soil microbiota undergo when exposed to triclosan
E) the reasoning for introducing waste water into the ecosystem studied

Only C is not addressed clearly. We do know that more studies must be undertake NOT is a good idea or less