In a study published online May 21, 2019 in the journal Environmental Research, researchers at University of California San Diego School of Medicine found higher blood pressure and pesticide exposures in children associated with a heightened pesticide spraying period around the Mother’s Day flower harvest.
This study involved boys and girls living near flower crops in Ecuador.
Mother’s Day is celebrated in May in most of the world and is a holiday with one of the highest sales of flowers. Ecuador is among the largest commercial flower growers in the world, with significant rose exports to North America, Europe and Asia.
Commercial rose production relies on the use of insecticides, fungicides and other pest controls, but little is known about their human health effects.
“These findings are noteworthy in that this is the first study to describe that pesticide spray seasons not only can increase the exposure to pesticides of children living near agriculture, but can increase their blood pressures and overall risk for hypertension,” said first author Jose R. Suarez, MD, Ph.D., assistant professor in the Department of Family Medicine and Public Health at UC San Diego School of Medicine.
The exposure of agricultural workers to pesticides is a public health problem worldwide.
The annual incidence of acute intoxication from pesticides is approximately 18 per 100,000 full-time farm workers (Thundiyil et al. 2008).
A large body of scientific evidence supports the existence of both acute and chronic effects of exposure to organophosphate (OP) pesticides, the most commonly used in chemicals for agricultural pest control, in agricultural workers (Alavanja et al. 2004; Garry 2004; Kamel & Hoppin 2004; Bradman & Whyatt 2005; Rothlein et al. 2006; Engel et al. 2007; Handal et al. 2007; Eskenazi et al. 2008; Jurewicz & Hanke 2008; Rosas & Eskenazi 2008).
Acute poisoning ranges from mild to fatal symptoms (Costa 2006), and manifests as headaches, nausea, respiratory problems, vomiting, bradycardia, miosis, dermatitis and burns.
Neurotoxic effects are associated with chronic exposures, especially cognitive, motor and sensory deficiencies and neurological diseases (Alavanja et al. 2004; Roldaán-Tapia et al. 2005; Joshaghani et al. 2007).
Studies have also found an association between OP pesticide use and emotional disorders (depression and anxiety), breathing difficulties, allergies, endocrine and immunotoxic effects, cancer, fetal abnormalities, and neurobehavioral and developmental delays in children of seasonal workers exposed to OP pesticides (Berkowitz et al. 2004; Eskenazi et al. 2004; Needham 2005; Engel et al. 2007; Eskenazi et al. 2007; Rosas & Eskenazi 2008; Muñoz-Quezada et al. 2013).
In Latin America, and specifically in Chile, there is limited data on OP pesticide exposure and health effects of the workers. Many OP pesticides used in Latin America are banned in the United States, Canada and Europe or their application is strictly regulated and controlled (Muñoz-Quezada et al. 2014).
The Maule Region is one of the regions in Chile with the largest rural population and has high rates of OP poisoning (Vallebuona 2006; Muñoz-Quezada et al. 2012).
The main objective of this study was to characterize the exposure to OP pesticides and health status of agricultural and other workers from the Maule Region.
Secondarily, variables related to pesticide poisoning symptoms were evaluated in the group of agricultural workers. This information may be used to guide the control and regulation of OP pesticides in Chile and other parts of Latin America.
Researchers assessed 313 boys and girls, ages 4 to 9, residing in floricultural communities in Ecuador.
The children were examined up to 100 days after the Mother’s Day harvest.
The analyses are part of a long-term study of environmental pollutants and child development in Ecuador, directed by Suarez.
“We observed that children examined sooner after the Mother’s Day harvest had higher pesticide exposures and higher systolic and diastolic blood pressures compared to children examined later.
In addition, children who were examined within 81 days after the harvest were three times more likely to have hypertension than children examined between 91 and 100 days.”
Research regarding the effects of pesticides on the cardiovascular system is limited, but Suarez said there is some evidence that insecticides, such as organophosphates, can increase blood pressure.
Organophosphates and several other classes of insecticides and fungicides are commonly used to treat flowers for pests before export.
rganophosphates and several other classes of insecticides and fungicides are commonly used to treat flowers for pests before export.
In a previous study, Suarez and colleagues had reported that children examined sooner after the harvest displayed lower performances in tasks of attention, self-control, visuospatial processing and sensorimotor than children examined later.
“These new findings build upon a growing number of studies describing that pesticide spray seasons may be affecting the development of children living near agricultural spray sites,” said Suarez.
“They highlight the importance of reducing the exposures to pesticides of children and families living near agriculture.”
Journal information: Environmental Research
Provided by University of California – San Diego
