Naled

Key takeaways

Naled belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Naled to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Naled from memory before moving on to harder problems.

Reference excerpt

Naled (Dibrom) is an organophosphate insecticide. Its chemical name is dimethyl 1,2-dibromo-2,2-dichloroethylphosphate. Naled is stable in anhydrous condition and must be stored away from light. It must also be stored under normal pressure and temperatures. It degrades in the presence of water and alkali, and produces toxic chloride fumes if exposed to acids or acidic fumes. Contact with metals, reducing agents, or sulfhydryls cause naled to release bromide and revert to dichlorvos.

Uses Naled is used primarily to control adult mosquitos. It is also registered to control black flies, and leaf eating insects on a variety of fruits, vegetables, and nuts. Approximately 70% of naled in USA is used in mosquito control, and approximately 30% in agriculture. Naled has also been used in veterinary medicine to kill parasitic worms in dogs. It has been used extensively within the United States since the 1950s. Naled was used in New Orleans after Hurricane Katrina, in North Carolina after Hurricane Florence (2018), and has been used historically in Puerto Rico to control dengue.

Toxicity The Environmental Protection Agency has determined that exposure levels from eating crops treated with Naled are below the level of concern. With higher exposures, however, naled can cause cholinesterase inhibition in humans, which in turn can overstimulate the nervous system causing nausea, dizziness, confusion, and at very high exposures, respiratory paralysis and death. It has the UN hazard classification of 6.1 (inhalation hazard) and is prohibited for use as an insecticide within the EU. Naled may cross the placenta if it is in the bloodstream of a mammal. Repeated exposures may also cause future behavioral problems, as well as issues with neurodevelopment, growth, and respiratory health in offspring. Chronic exposure to dichlorvos, a metabolite of naled, has also been linked to neurological issues, such as Parkinson's disease and nigrostriatal dopaminergic degeneration. Persons who work closely with naled or other organophosphate pesticides should undergo regular testing of their cholinesterase levels. EPA classifies naled as Group E or non-carcinogenic for humans. Neither naled nor its metabolite, dichlorvos, build up in breast milk or breast tissue. In a 2017 general-population study of the chemical, University of Michigan researchers found that children in China who had the highest prenatal exposure to naled had, at age 9 months, 3% to 4% lower scores on tests of their fine motor skills, compared with those with the lowest exposure.

Ecological effects Naled is considered highly toxic to bees, as well as being moderately to highly toxic to birds and toxic to most aquatic life. Naled is also toxic to butterflies at amounts typically used to control mosquitoes. The mule deer is among those most resistant to its effects.

2015–16 Zika virus epidemic Aerial spraying of naled has been recommended by the Centers for Disease Control and Prevention and United States Environmental Protection Agency for the prevention of the spread of the Zika virus in the United States. Experts at both the CDC and EPA, as well as independent universities, have argued that naled is safer than other chemicals and should not cause significant health issues due to the low level of exposure. The federal government had considered using the chemical in Puerto Rico to stop the spread of Zika, but decided against it due to the potential danger to pregnant women. Its proposed use against Zika led to protests in Puerto Rico. Miami is using specialized trucks to spray naled and Bacillus thuringiensis israelensis (BTI). Governor Rick Scott said that the CDC recommended using helicopters to spray the insecticides, but some people in Miami and Miami Beach are opposed to aerial spraying. Spraying of naled in Dorchester County, South Carolina purportedly led to the deaths of 3 million honeybees and increased criticism by beekeepers. Beekeepers in the county complained that they had not been notified of spraying before it happened. Juanita Stanley, a beekeeper and co-owner of Flowerton Bee Farm and Supply, told CNN, "Now, I'm going to have to destroy my hives, the honey, all my equipment. It's all contaminated." Jennifer Holmes, vice-president of the Florida State Beekeepers Association, compared the loss of bees to other forms of agriculture, saying, "If there was a regulation that allowed some spraying that would kill half of your livestock overnight, how would you recover?" She went on to say that "we understand the serious threat of possible disease, but we also have to maintain our agricultural livelihood.”

See also Malathion - another insecticide sprayed from the air to control mosquitos Bacillus thuringiensis israelensis - a biological control agent sprayed from the air to control mosquitos

References

Illustrations

Worked examples

Example 1 — a first encounter with Naled

Start with the simplest possible case. Write down what Naled claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Naled before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Naled ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Naled

In research: Naled appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Naled in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Naled is common in secondary-school and first-year university syllabi. It links to neighbouring topics Acetylcholinesterase inhibitors, Methyl esters, Neurotoxins, so understanding it makes those chapters shorter.
In everyday life: Look for Naled outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Naled in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Naled means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Naled out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Naled in simple terms?

Naled (Dibrom) is an organophosphate insecticide. Its chemical name is dimethyl 1,2-dibromo-2,2-dichloroethylphosphate.

Why does Naled matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Naled?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Naled.