Pesticide exposure and ocular toxicity

Pesticide residues accumulate in homes with higher amounts that are found in the Child Breathing Zone. Negative health effects are known to exist from exposure to pesticide residues, including ocular toxicity. This paper reports on a study of pesticide residues found in a random sample of 132 homes in non-metropolitan counties of New York State. Fifteen pesticides were tested for and residues from all fi fteen pesticides were found in all 132 homes. Potential consequences of human exposure to these residues are discussed as is a potential remedy. Research Article Pesticide exposure and ocular toxicity Joseph Laquatra* Ph.D, Professor Emeritus, Department of Design and Environmental Analysis, Cornell University, Ithaca, NY, USA Received: 17 February, 2020 Accepted: 06 April, 2020 Published: 07 April, 2020 *Corresponding author: Joseph Laquatra, Ph.D, Professor Emeritus, Department of Design and Environmental Analysis, Cornell University, Ithaca, NY, USA, E-mail:

in the CBZ. There is no current IAQ management system that specifi cally focuses on improving IAQ in the CBZ.
Exposure to pesticides poses health risks to humans, especially infants and children [6]. Babayigit, Tekbas, and Cetin [7] reported that these risks include cancer, birth defects, nervous system disorders, and endocrine system disorders.
Obendorf, et al. [8] listed adverse health effects from exposure to organophosphate pesticides and carbamates as depressed cholinesterase in red blood cells and death at high enough exposure levels. Jaga and Dahrmani [2] described pesticiderelated damage to eyes. Ocular toxicity results from exposure routes that include ocular and oral exposure and dermal contact. Toxic effects include irritation, blurry vision, burning feelings, and eye watering. Toxicity affects the cornea, retina, lens, conjunctiva, and optic nerve.
Studies of pesticide residues in homes have documented entry routes that include tracking with shoes, bare feet, clothing, or animal fur; airborne entry; and soil gas entry [9,10]. Adjacency and proximity to agricultural operations have also been cited as factors responsible for residential pesticide residues because of spray drift and volatility [11]. Lawn-applied pesticides can follow these same transport routes [10]. Once inside a home, pesticide residues accumulate in dust and degrade at a lower rate than they do outdoors because they are shielded from the effects of rain, sun, and soil microbial activity [12].

Introduction
Pesticide residues are ubiquitous in home environments [1]. A wide range of adverse human health impacts can occur through exposure to these residues including cancer, birth defects, leukemia, and ocular toxicity [2]. For physiological and behavioral reasons, children are at a higher risk than adults for both exposure to environmental toxicants and for adverse health effects from those toxicants [3]. Children are more highly exposed to environmental pollutants than adults because they breathe more air per pound of body weight and chew or suck on toys and hands that have been in contact with pollutants [4].
Babies crawl on the fl oor and young children walk, run, and play on the fl oor; thus, the breathing zone of children is much lower (up to 1 m from the fl oor). This zone is known as the Child Breathing Zone (CBZ). Resuspension of respirable particulates, including pesticide residues, is caused by walking-induced turbulence in a room, and shorter people are exposed to more resuspended particulates than taller people. Tripathii and Laquatra [5] showed that indoor air quality can be signifi cantly

Methods
To examine the extent of indoor pesticide pollution in rural homes, pesticide sampling and analyses were conducted as part of a larger effort that studied pollutants in homes and childcare facilities [13]. Fifteen pesticides with a likelihood of accumulation in the interiors of rural homes were selected for this study. Researchers involved with this study received approval to proceed from the Cornell University Institutional Review Board.
A two-stage random sampling procedure was used to obtain a representative sample of households in all non-metropolitan counties in New York State. A hierarchical cluster analysis using average linkage methods [14] was performed on the twenty- conditions. The effl uent was manually collected and condensed for GC/MS analysis. Acetone was used to extract fi lter paper samples for GC/MSD analysis. Pesticides were analyzed on a HP5890 Series II gas chromatograph coupled to a HP 5971A MS (Agilent Technologies, Sunnyvale, CA). Hong, et al. [15] detail the operating conditions. Characteristic MS fragment ions and chromatographic retention times were used to identify pesticides by matching. Quality assurance methods described by Hong, et al. [15] were followed.
Acid pesticides were taken out of dust with distilled water and calcium hydroxide. PH was adjusted (1 to 2) and effl uent cleaned by solid phase extraction with a polyvinyl benzene/ polystyrene cartridge. The cartridge was washed with distilled water at pH 2 and eluted with methanol in MTBE. The solution was extracted with diethyl ether. The extract was dried, followed by addition of methanol and trimethylsilyl diazomethane to methylate the carboxylic acid pesticides.
Acidifi ed acetone (3 mM H3PO4) was extracted with fi lter paper samples. The extract was condensed, methylated, and injected into the GC in the same way as dust extract except SPE cleanup was not used. Optimized GC/MS conditions were similar to those for non-acid pesticides [15].
Pesticide residue results from the non-carpeted areas are presented in Table 1. Note that residues of each pesticide tested for were found in every home in the sample.

Discussion
The fact that pesticide residues were found in every house tested in our sample indicates the ubiquitous nature of these chemicals in the rural environment. Similar fi ndings were also Regarding the other pesticide residues observed, Picloram Acid is classifi ed by the U.S. Environmental Protection Agency (EPA) as a Restricted Use Pesticide that has been shown to be of moderate to low acute toxicity [18]. Atrazine has been shown to cause reproductive problems [19]. Human exposure to large amounts of carbaryl can be toxic to nervous and respiratory systems [20]. Prowl is classifi ed by the EPA as a possible human carcinogen [21]. Pyrethroids are associated with nervous system damage [22]. Alachlor has the potential to cause cancer in laboratory animals [23]. Trifl uralin can cause allergic dermatitis from prolonged exposure [24]. Metolachlor is slightly toxic if ingested [25]. 2,4D-acid may cause birth defects at high doses [26].
McCaule, et al. [27] reported that residential cleaning practices can signifi cantly reduce pesticide residues, but those practices are specifi c to different surfaces. This indicates that educators involved in pesticide education programs may want to include program elements that include home maintenance guidelines for prevention of and safe eradication of accumulated pesticide residues of which consumers may not be aware. This could be an important component of public health education efforts.