Health Department Spraying for Mosquitoes on UWS Monday Night; ‘Stay Indoors If You Can’ (Updated)

Section of Manhattan to be sprayed is shown in yellow. Courtesy of DOHMH.

By Carol Tannenhauser

This Monday night, September 27, from 8:30 PM to 6:00 AM, Tuesday morning, the NYC Department of Health and Mental Hygiene (DOHMH) will be conducting “ground-based spraying of mosquito larvicide” in parts of Manhattan and Staten Island, including zip codes 10023, 10024, and 10025 on the Upper West Side, and all of Central Park.

The reason is to “reduce mosquito activity and the risk of West Nile virus,” according to a press release. Every summer the city monitors mosquito populations and applies pesticide when testing has shown a high risk to human health. “We spray in response to West Nile virus being found in mosquitoes in an area through our trap surveillance program,” explained Michael Lanza, a spokesperson for DOHMH. The city will use a method called “Adulticide,” in which trucks spray pesticide to kill adult mosquitoes. Spraying occurs in the evening in residential areas and parks.

Update: Lanza says that the spraying is expected to begin after midnight. “Our folks usually just start setting up around 8pm but won’t start spraying until later at night (or morning) when most people are inside their homes.”

In case of inclement weather, the alternate time for the spraying will be between 8:30 PM on Tuesday, September 28, and 6:00 AM on Wednesday, September 29.

Are there risks associated with the pesticide? Should we stay inside? Actually, yes, if you can.

”Encourage readers to stay indoors during the spray event,” Lanza said, “though if they are outside, they should just wash up and make sure to also wash any non-packaged food items they may have had on hand when outdoors, like fruits and vegtables.”

“The Health Department will use very low concentrations of Anvil, Duet, or DeltaGard,” the press release continued. “The risks of pesticides applied by DOH for mosquito control are low to people and pets. Some people who are sensitive to spray ingredients may experience short-term eye or throat irritation, or a rash. People with respiratory conditions may also be affected….. Air conditioners can remain on [during the spraying.] While unnecessary, you may wish to close air conditioner vents, or choose the recirculate function.

“The most effective way to control mosquitoes is to eliminate any standing water,” says DOHMH. “New Yorkers are also encouraged to mosquito-proof their homes and take precautions when spending time outdoors.”

Here are some ways to reduce exposure to mosquitoes:

Use an approved insect repellent containing DEET, picaridin, oil of lemon eucalyptus (not for children under 3), or products that contain the active ingredient IR3535.

Make sure windows have screens. Repair or replace screens that have tears or holes.

Eliminate any standing water from your property and dispose of containers that can collect water.

Standing water is a violation of the New York City Health Code.

Make sure roof gutters are clean and draining properly.

Clean and chlorinate swimming pools, outdoor saunas and hot tubs. Keep them empty or covered if not in use. Drain water that collects in pool covers.

Report standing water by calling 311 or visiting For more information about West Nile virus, call 311 or visit

NEWS | 25 comments | permalink
    1. care4u says:

      What about the homeless?
      Where are they supposed to be?
      Outdoors, that’s where.

      • Pat W says:

        So unnecessarily nasty to the homeless.

        • Leon says:

          I don’t think that was nasty to the homeless, I think it was bringing attention to the fact that the homeless are being impacted by this and no one cares. Everyone is looking for an argument these days…

          Nice haiku.

        • care4u says:

          Nasty says as nasty does.
          I care about the homeless.
          That’s why I brought this up.
          You are so negative in your mind that instantly you hear/see NASTY.
          Shame on you.

      • Tory Phillips says:

        How could someone misunderstand this?

    2. Mark Moore says:

      I might prefer the mosquitos.

    3. nyc10023 says:

      isn’t peak mosquito season like mid-summer?

    4. PaulCons says:

      Why is the area west of Columbus, including Riverside Park excluded from spraying?

    5. Lisa says:

      No one is forcing people to sleep on the street. NYC provides overnight shelter to those without homes. That many do not avail themselves of this option does not mean that spraying should not take place.

      • Bob says:

        I had a friend whom was homeless. He would rather have slept in the street than go to a shelter. The spraying however will protect the homeless from the nile virus as they are constantly outside.

    6. ben says:

      Seems a bit late, no? That said I’ve definitely noticed more mosquitoes this summer than recent past.

    7. UWS girl says:

      Given the recent record rains and mild days this seems important.

    8. Barbara Aubrey says:

      It would be nice if the city cleared all drains. Many times after a rainfall street drains are clogged, the street gets flooded and water does not evaporate for days.

    9. Robin Peterson says:

      Are all the vegetable stands aware they should cover up there merchandise?
      I guess you should always wash your produce…..especially now!

    10. LivableCity says:

      Thank you WSR for both post and update. I sent this to a few people including some in the spray zone. No one had heard. I was shocked buildings didn’t have notices up. In this nice weather a lot of people keep windows open. But keeping them shut tonight between 12 and 6 is what most informed folks will want to do. At least it gets light later so the early dog walkers won’t be out mostly til after 6:30.

    11. marianne says:

      2 people here remarked that summer is over and why spray now. I agree. Beyond that I did the following research:

      Fact is, summer is over, mosquitoes die when it’s around 50 degrees which it will be in a few nights . I’ve been outside every evening and for at least a week no more mosquitoes. So why are they doing it? Makes no sense. The poisons they are spraying are:
      a) Anvil: “Endocrine disruptors” are chemicals that interfere with endocrine system function. The endocrine system consists of glands that produce hormones that act together to guide development, growth, reproduction and behavior, and to maintain normal organ function.
      b) DeltaGard (called “Adulticide- freaky!) is neurotoxic. Pyrethroids like Deltamethrin can be allergens and cause asthma in some people.
      In addition to that what about the ecosystem? I don’t hear any birds anymore;-((

      here’s some research:

      This report discusses how pesticides, such as pyrethroids, used for mosquito control, are not effective control agents and at the same time are harmful to human health. “Adulticiding, or spraying to kill adult mosquitoes, has not yet been proven effective. The Centers for Disease Control and Prevention state that ground and aerial spraying is usually the least effective mosquito control technique1” (p.3). Also included in the report are health effects of pyrethroids such as “asthmatic breathing, sneezing, nasal stuffiness, headache, nausea, incoordination, tremors, convulsions, facial flushing and swelling, and burning and itching sensations” (p.9). “Pyrethroid insecticide poisoning can be of unexpectedly long duration. Pyrethroids can produce reflex hyperexcitability and fine tremor, salivation, choreoathetosis (involuntary movements), and seizure” (p.9). “Several studies indicate that pyrethroids disrupt the endocrine system by mimicking the effects of the hormone estrogen, which can cause breast cancer in women and lowered sperm count in men” (p.9).
      An article from Environmental Health Perspectives referred to in the report concludes, “the specific chemicals associated with children’s brain cancer were pyrethrins and pyrethroids (which are synthetic pyrethrins, such as permethrin, tetramethrin, allethrin, resmethrin and fenvalerate) and chlorpyrifos”2 (p.10). “Northwestern University Medical School conducted a series of investigations at Northwestern’s Department of Molecular Pharmacology and Biological Chemistry in Chicago, and has found neurological damage from pyrethroids”. (p.10)

    12. Back in the day there were NO mosquitoes in my UWS apt. Not a one… and even then, they were just mosquitoes: an itch.

      Now they’ve become Killers.

      Gradually mosquitoes came to be seen, almost drifting in the air, ghost-like… then they came to stay in their ones and twos weeks apart; now I see them EVERYDAY in the summer, all summer long, every summer… and the summers are longer and longer.

      I see them and but what’s worse is I hear them, at night, when I’m asleep SUDDENLY in my ear which I SLAP hard and then I’m WIDE AWAKE, my stupid head RINGING…

      aware that I’m something’s blood meal.

      And I’m UP! Hunting the walls with flashlight and swatter and if I’m very lucky BANG!

      And then I’m looking at a big splotch of my own red blood now painting a blue wall. And, if after 15 minutes of hunting I can’t find where it eventually alighted?

      Then I lie down with the swatter I’m now forced to now sleep with, and lie there waiting for either that damn sound or some uneasy sleep to befall me so that I can become an unconscious blood donor again.

      I called Linda Rosenthal’s office some years back, several times, and got an earful of happy talk: “Yes we’re certainly on it, we know all about it, and we’ll certainly call you back”.

      Sure you will; perhaps sometime after the first of NEVER?

      Still waiting, still swatting.

      And now they’re gonna spray… in the AUTUMN?

      How very special.

    13. Barbara E Morgan says:

      Talk about “closing the barn door after the horse has run out!” The mosquitoes have been awful this summer in Riverside Park, and I have never heard of any spraying there. And, they are not deterred by repellent.

    14. JL says:

      WSR, please confirm if this happened last night. It would make more sense to spray after today’s rain as larvaes(larvicide) need standing water to hatch and spraying before the rain would mean the poison would be washed away.

    15. Eleanor Dodds says:

      How long after spraying should windows remain closed?

    16. RAK says:

      How about Riverside Park!?!

    17. Ian Alterman says:

      It is simply mind-boggling to me how EVERYTHING becomes politicized now.

      The reason they are spraying is that, no, not all mosquitoes die (acutally, they simply become inactive) after it is 50 degrees. SOME do, some don’t. And those that don’t are the most virulent – which is what they are spraying for.

      Second, mosquitoes breed where it is damp or wet. Like lakes and such. Like they have in Central Park. That is why it is the area around CP that is being sprayed. Because that is where the mosquitoes are breeding. They don’t spray Riverside Park because it doesn’t have any lakes, streams, or other water sources (and the Hudson River doesn’t count).

      Third, the homeless have been with us since at least the 1960s. And spraying for mosquitoes has been done every year or two for decades. They know about it, and are aware of it, and simply avoid the CP area for that period (I know this because I have worked with the local homeless for over two decades).

      So everyone take a chill pill. There is nothing new about spraying for virulent mosquitoes (and other flying insects; I have personally had a bigger issue with biting gnats this year), particularly in late Summer/early Fall.

    18. Lisa says:

      Marianne who commented above is providing the facts on the dangers of these toxic pesticides. She is absolutely right. There are nontoxic methods for dealing with mosquitoes that are 100% effective. Why decision-makers always go the cheapest, most harmful route in this country, I will never understand. All these chemicals we use in this country are banned in Europe for the sole reason that they are toxic to human health. More awareness and funding needs to be brought for nontoxic solutions. America loves its toxic chemicals. And the fact that most people don’t even question the use is a huge part of the problem. These are the same people who use toxic dryer sheets, Pine-Sol, and Raid, and then are later upset and confused when they get cancer. It’s truly mind boggling.

      • Marianne says:

        Lisa, I agree wholeheartedly with you. The cheapest and most toxic way… Today an 80- year old friend of mine went to riverside park and reported the following: “ I played Kadima at the baseball field with a friend this afternoon. Everything was fine, while we were playing in the sand. But when the Little Leaguers arrived to play baseball, we had to move to the grassy area. After a while, I started to smell something weird, like cheap perfume or cheap aftershave, especially when I bent down to pick up a ball. Then I realized that the smell emanated from the ground. I started to get a headache and had to spit a lot. Finally I realized that we must be in a toxic sprayed area. We got out of there quickly. While walking along the track, I saw the kids playing soccer in the infield , some rolling in the grass. No signs warning anyone like they used to do. “ I went down to riverside park myself and my nose became runny and I got a bad headache also within a half hour and also smelled this cheap perfume – type smell coming from the grassy area that’s surrounded by a running track around 73rd street. Very concerning.

        • Lisa says:

          Marianne, that story is so scary. And to have the kids running around, likely falling with their faces close to the grass, is a frightening thought. It’s so irresponsible that the city did this in the first place, and then did not post signs about it. The “toxic broad brush approach” to the mosquitoes is really overkill. The chemical lobby is so strong in this country. The environmental and health groups can’t keep up. We need more physicians to come forward and lobby against these toxic chemicals, but they rarely do.