Pesticides, Asthma, and the Community-Researcher Dialogue
By Benjamin Sipes
The EPA registers 36 organophosphorus (OP) pesticides for use in the United States, and while all of them pose potential health risks, perhaps the most contentious is the OP chlorpyrifos. “Chlorpyrifos is the pesticide--the OP pesticide—that has generated a lot of concern in the United States because it has been used very widely,” says Dr. Pamela Lein, a neurotoxicologist at the University of California, Davis. “Chlorpyrifos is one of the most widely used OPs for agriculture in the world,” continues Dr. Lein. And although the EPA no longer approves the pesticide for home use, “there are still a number of schools that are within the vicinity of chlorpyrifos and other OP pesticides being sprayed in agricultural fields.”
Chlorpyrifos is used on a variety of fruits and vegetables, but some of the most prominent include apples, peaches, bell peppers, almonds, and cranberries. While chlorpyrifos residue ingested from food is a concern, perhaps more important is that chlorpyrifos attaches itself to dust particles. Despite the EPA requiring a 300-foot “buffer” wherever the pesticide is sprayed, dust with chlorpyrifos attached can travel much farther.
In November of 2016, the EPA released a memorandum describing their current understanding of chlorpyrifos and implemented regulations to restrict it. The EPA announced that there would be a decision on whether to ban chlorpyrifos by March 31st of 2017. However, on March 29th, two days before their original deadline, the EPA decided not to take any action. They claimed that there was still too much doubt about the science, despite multiple studies asserting adverse health outcomes. The EPA deferred their decision until 2022, but researchers and advocates aren’t giving up making their case and implementing local regulations.
Dr. Pam Lein from UC Davis has already begun to explore the impact of chlorpyrifos on animals, with her findings already suggesting adverse effects. Among the pesticide’s many negative effects, including a reduction in IQ, decreased working memory ability, and an association with Autism Spectrum Disorder, Dr. Lein’s previous work shows evidence that chlorpyrifos may be a contributing factor to the increased prevalence of asthma.
Dr. Lein and her project scientist, Dr. Cris Grodzki, are about to begin a project examining the asthmatic effects of chlorpyrifos using infant and juvenile rats as a pre-clinical model. Working in dialogue with the California Department for Pesticide Regulation (DPR), Dr. Lein and Dr. Grodzki hope to conduct research that informs regulatory policy and increased awareness in the communities using chlorpyrifos and other OP pesticides.
Dr. Lein’s interest in toxins like chlorpyrifos started when she was an environmental science major at Cornell University. She became fascinated with the poisonous plant garden at Cornell’s veterinary school where her father was a professor. “I decided to take a course in poisonous plants while I was there, and that is how I was introduced to the concept of toxicology,” says Dr. Lein. She began to see many problems in society that revolved around chemical effects on biological systems. To her, understanding “how chemicals modify biology and how that manifests at the organism level,” is a puzzle, and she loves puzzles.
Dr. Grodzki first met Dr. Lein when she moved to California after a post-doc at the National Institutes of Health (NIH). Dr. Grodzki found an ad for a position in Dr. Lein’s lab, and although she didn’t fit the exact position advertised, her background in cell biology and immunology made her a valuable addition to the lab. “So I joined first as a post-doc and learned, being in the lab, the neurotoxicity part of it,” says Dr. Grodzki.
Understanding the intersection between neurotoxicity, immunology, and lung health is crucial to understanding how pesticides influence asthma. “Cris brings a wealth of background in immunology, which is critical to this project,” says Dr. Lein, “and I have toxicology expertise. We have trained each other, so I know more about immunology now, she knows more about toxicology now. It is very much a team effort.”
The idea for the project dates back to Dr. Lein’s time as a faculty member at Johns Hopkins University. A colleague sparked her interest in the possibility that OPs could change the way neurons develop, and after their collaboration, that is exactly what they found. “At the time, the epidemiological data was really coming out that organophosphorus pesticides pose a risk to the developing human brain, which we now accept, but back in those days, it was pretty controversial,” says Dr. Lein.
Many identified environmental factors cause airway hyperactivity, the major symptom of asthma, through changing neuron morphology in the lung. After discovering OPs indeed change neurons, Dr. Lein found that they also induce airway hyperactivity. But, perhaps more significantly, they caused airway hyperactivity at levels lower than what the EPA would find concerning.
OPs poison the body by inhibiting an enzyme in our blood and brain known as acetylcholinesterase. “The California EPA, California OSHA, and California Workers Protection all measure safe exposure by measuring blood cholinesterase levels,” says Dr. Lein. “But what is really important about our finding is that we see these OPs cause asthma at concentrations that do not inhibit blood cholinesterase.”
The next step in Dr. Lein and Dr. Grodzki’s investigation is to observe how OPs affect children as they mature. They will expose rats as infants to chlorpyrifos through a subcutaneous (just beneath the skin) injection, which releases slowly and is designed to mimic dermal contact with OPs in dust. Dermal exposure from dust, opposed to oral exposure from food, is thought to be the primary way that kids are exposed to pesticides. The dust attaches to kids’ stuffed toys, it settles on the floors where they crawl, and it is in the air outside, coating surfaces where they play.
To make their findings relevant to pesticide regulation, Dr. Lein and Dr. Grodzki contacted several community stakeholders for their support. The California Department of Pesticide Reform (DPR) is one of the key stakeholders involved. “They are probably going to be our major consumer, because of the level of information, they can use [our data] immediately in terms of regulatory decisionmaking regarding chlorpyrifos. So this is very timely,” says Dr. Lein.
“We are very excited,” says Dr. Grodzki, “I think it is an important part of science to communicate to the people who have the most interest [and are] the most affected.”
“It is important for us as scientists to be better integrated into the general community and for us to educate the community as to the value of what we can provide,” adds Dr. Lein, “but also to listen to them so that we can provide the information they find of value.”
Despite Dr. Lein’s and Dr. Grodzki’s enthusiasm about their research influencing public policy, it is also their first time working in conjunction with community stakeholders, and the process hasn’t been easy.
“The very first conversation we had was interesting,” says Dr. Lein, describing her and Dr. Grodzki’s first conference call with the DPR and two other community stakeholders. “These were all high-level people within those organizations who have been doing community outreach for quite a while, and they came in with a preconceived notion of how this was going to work,” continues Dr. Lein.
As they began to describe their plans for the project, the stakeholders began to critique their methodological decisions, such as their using a subcutaneous exposure or even their decision to investigate chlorpyrifos at all. Instead, the community stakeholders told her that she should be looking at fungicides and fumigants effects in humans. “They were very definitive, ‘This is what we want you to do,’” says Dr. Lein, emphasizing the difficulties in communication between them.
“I had to step in and say: these are all great ideas, but A, we are not epidemiologists, we do animal research. And B, there is actually really good scientific reason why we are doing subcutaneous exposure, and that dermal inhalation is not feasible for the following reasons,” explained Dr. Lein, “So it really was a give and take. And I think at the end, we all came with a better sense of what everyone else was bringing to the table.”
Many scientists face similar difficulties in communication when first working with community organizers. As this is her first time, Dr. Lein offered some advice to any other university faculty interested in community engaged research—“don’t be scared,” she says. “Engage the people who know how to [work with community organizations] effectively. Being part of the EHS Center has been very helpful in getting us engaged in a way where we feel we can actually do it.”
After the March 29th decision not to place any bans on chlorpyrifos, the relevance of Dr. Leins project became increasingly salient. Dr. Lein cannot offer the community stakeholders everything they want, but she is still excited that they have come to an understanding and that her research can still be useful.
To enact local change, researchers and community organizers need to work together. These partnerships may be a source of friction due to misunderstandings on both sides, but increased collaboration will smooth the process while better integrating scientifically informed policies into the broader community. In the end, it all comes back to communication. “I do think there is still a lot of room for learning on both sides,” says Dr. Lein, “and learning about what each side is capable of doing in addition to the desire to do it.”
Chlorpyrifos is used on a variety of fruits and vegetables, but some of the most prominent include apples, peaches, bell peppers, almonds, and cranberries. While chlorpyrifos residue ingested from food is a concern, perhaps more important is that chlorpyrifos attaches itself to dust particles. Despite the EPA requiring a 300-foot “buffer” wherever the pesticide is sprayed, dust with chlorpyrifos attached can travel much farther.
In November of 2016, the EPA released a memorandum describing their current understanding of chlorpyrifos and implemented regulations to restrict it. The EPA announced that there would be a decision on whether to ban chlorpyrifos by March 31st of 2017. However, on March 29th, two days before their original deadline, the EPA decided not to take any action. They claimed that there was still too much doubt about the science, despite multiple studies asserting adverse health outcomes. The EPA deferred their decision until 2022, but researchers and advocates aren’t giving up making their case and implementing local regulations.
Dr. Pam Lein from UC Davis has already begun to explore the impact of chlorpyrifos on animals, with her findings already suggesting adverse effects. Among the pesticide’s many negative effects, including a reduction in IQ, decreased working memory ability, and an association with Autism Spectrum Disorder, Dr. Lein’s previous work shows evidence that chlorpyrifos may be a contributing factor to the increased prevalence of asthma.
Dr. Lein and her project scientist, Dr. Cris Grodzki, are about to begin a project examining the asthmatic effects of chlorpyrifos using infant and juvenile rats as a pre-clinical model. Working in dialogue with the California Department for Pesticide Regulation (DPR), Dr. Lein and Dr. Grodzki hope to conduct research that informs regulatory policy and increased awareness in the communities using chlorpyrifos and other OP pesticides.
Dr. Lein’s interest in toxins like chlorpyrifos started when she was an environmental science major at Cornell University. She became fascinated with the poisonous plant garden at Cornell’s veterinary school where her father was a professor. “I decided to take a course in poisonous plants while I was there, and that is how I was introduced to the concept of toxicology,” says Dr. Lein. She began to see many problems in society that revolved around chemical effects on biological systems. To her, understanding “how chemicals modify biology and how that manifests at the organism level,” is a puzzle, and she loves puzzles.
Dr. Grodzki first met Dr. Lein when she moved to California after a post-doc at the National Institutes of Health (NIH). Dr. Grodzki found an ad for a position in Dr. Lein’s lab, and although she didn’t fit the exact position advertised, her background in cell biology and immunology made her a valuable addition to the lab. “So I joined first as a post-doc and learned, being in the lab, the neurotoxicity part of it,” says Dr. Grodzki.
Understanding the intersection between neurotoxicity, immunology, and lung health is crucial to understanding how pesticides influence asthma. “Cris brings a wealth of background in immunology, which is critical to this project,” says Dr. Lein, “and I have toxicology expertise. We have trained each other, so I know more about immunology now, she knows more about toxicology now. It is very much a team effort.”
The idea for the project dates back to Dr. Lein’s time as a faculty member at Johns Hopkins University. A colleague sparked her interest in the possibility that OPs could change the way neurons develop, and after their collaboration, that is exactly what they found. “At the time, the epidemiological data was really coming out that organophosphorus pesticides pose a risk to the developing human brain, which we now accept, but back in those days, it was pretty controversial,” says Dr. Lein.
Many identified environmental factors cause airway hyperactivity, the major symptom of asthma, through changing neuron morphology in the lung. After discovering OPs indeed change neurons, Dr. Lein found that they also induce airway hyperactivity. But, perhaps more significantly, they caused airway hyperactivity at levels lower than what the EPA would find concerning.
OPs poison the body by inhibiting an enzyme in our blood and brain known as acetylcholinesterase. “The California EPA, California OSHA, and California Workers Protection all measure safe exposure by measuring blood cholinesterase levels,” says Dr. Lein. “But what is really important about our finding is that we see these OPs cause asthma at concentrations that do not inhibit blood cholinesterase.”
The next step in Dr. Lein and Dr. Grodzki’s investigation is to observe how OPs affect children as they mature. They will expose rats as infants to chlorpyrifos through a subcutaneous (just beneath the skin) injection, which releases slowly and is designed to mimic dermal contact with OPs in dust. Dermal exposure from dust, opposed to oral exposure from food, is thought to be the primary way that kids are exposed to pesticides. The dust attaches to kids’ stuffed toys, it settles on the floors where they crawl, and it is in the air outside, coating surfaces where they play.
To make their findings relevant to pesticide regulation, Dr. Lein and Dr. Grodzki contacted several community stakeholders for their support. The California Department of Pesticide Reform (DPR) is one of the key stakeholders involved. “They are probably going to be our major consumer, because of the level of information, they can use [our data] immediately in terms of regulatory decisionmaking regarding chlorpyrifos. So this is very timely,” says Dr. Lein.
“We are very excited,” says Dr. Grodzki, “I think it is an important part of science to communicate to the people who have the most interest [and are] the most affected.”
“It is important for us as scientists to be better integrated into the general community and for us to educate the community as to the value of what we can provide,” adds Dr. Lein, “but also to listen to them so that we can provide the information they find of value.”
Despite Dr. Lein’s and Dr. Grodzki’s enthusiasm about their research influencing public policy, it is also their first time working in conjunction with community stakeholders, and the process hasn’t been easy.
“The very first conversation we had was interesting,” says Dr. Lein, describing her and Dr. Grodzki’s first conference call with the DPR and two other community stakeholders. “These were all high-level people within those organizations who have been doing community outreach for quite a while, and they came in with a preconceived notion of how this was going to work,” continues Dr. Lein.
As they began to describe their plans for the project, the stakeholders began to critique their methodological decisions, such as their using a subcutaneous exposure or even their decision to investigate chlorpyrifos at all. Instead, the community stakeholders told her that she should be looking at fungicides and fumigants effects in humans. “They were very definitive, ‘This is what we want you to do,’” says Dr. Lein, emphasizing the difficulties in communication between them.
“I had to step in and say: these are all great ideas, but A, we are not epidemiologists, we do animal research. And B, there is actually really good scientific reason why we are doing subcutaneous exposure, and that dermal inhalation is not feasible for the following reasons,” explained Dr. Lein, “So it really was a give and take. And I think at the end, we all came with a better sense of what everyone else was bringing to the table.”
Many scientists face similar difficulties in communication when first working with community organizers. As this is her first time, Dr. Lein offered some advice to any other university faculty interested in community engaged research—“don’t be scared,” she says. “Engage the people who know how to [work with community organizations] effectively. Being part of the EHS Center has been very helpful in getting us engaged in a way where we feel we can actually do it.”
After the March 29th decision not to place any bans on chlorpyrifos, the relevance of Dr. Leins project became increasingly salient. Dr. Lein cannot offer the community stakeholders everything they want, but she is still excited that they have come to an understanding and that her research can still be useful.
To enact local change, researchers and community organizers need to work together. These partnerships may be a source of friction due to misunderstandings on both sides, but increased collaboration will smooth the process while better integrating scientifically informed policies into the broader community. In the end, it all comes back to communication. “I do think there is still a lot of room for learning on both sides,” says Dr. Lein, “and learning about what each side is capable of doing in addition to the desire to do it.”