W6

Running head: TOXIC CHEMICALS AND LEARNING DISABILITIES 1

Toxic Chemicals and the Impact on Students with Learning Disabilities

Liberty University

TOXIC CHEMICALS AND LEARNING DISABILITIES 2

Abstract

Research has shown possible links between toxic chemicals and learning disabilities, Attention

Deficit Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD), and dyslexia.

Chemical exposure happens indoors and outdoors, and studies have shown that schools are no

exception (Cometto-Muñiz & Abraham, 2015). Some school administrations have begun

removing toxic chemicals to make their schools healthier and safer (Environmental Protection

Agency, 2018a). The quality of air inside of schools could be playing a role for children with

ADHD, ASD, dyslexia, and other learning delays, especially with indoor pollution being up to

100 times as high as outdoor (EPA, 2018b) and more and more children are staying indoors each

day. Not only is indoor air quality a concern, but so is the ingestion of chemicals through food

and beverages (Judge et al., 2017). With one in every six children developing learning

disabilities (Bennett et al., 2016), finding ways to prevent and intervene is critical for student

success. Most chemicals are unregulated and do not undergo testing for toxicity or

neurodevelopmental effects (Berman, 2014). Despite the research linking chemicals with

neurodevelopmental problems, not much is being done to produce changes. More in-depth

research is needed to determine which chemicals disturb the endocrine system and cause

neurodevelopmental problems. Otherwise, the rising numbers of diagnoses might continue to

climb. Toxic cleaning products, deodorizers, disinfectants, soaps, and perfumes should be

removed from schools and replaced with green alternatives. Prevention should become a high

priority for the sake of children world-wide.

Keywords: learning disabilities, ADHD, ASD, dyslexia, toxic chemicals, schools

TOXIC CHEMICALS AND LEARNING DISABILITIES 3

Toxic Chemicals and the Impact on Students with Learning Disabilities

According to Lanphear (2015), while the brain is still developing, it is significantly

exposed to environmental contaminants. The area that protects the brain is not fully developed,

which makes it more penetrable to chemicals than a brain that is fully developed. While cells are

growing, they are more defenseless against toxins, and it takes the brain a lot longer to develop

fully than other organs in the human body. The brain has several phases of growth, each with

diverse profiles of toxicity.

According to Berman (2014), recent increases in the number of brain disorders in

children, may be caused from the use of toxic chemicals world-wide, all of which are

unregulated. Brain disorders affected by these chemicals include ADHD, dyslexia, cerebral

palsy, and ASD. Berman adds that six chemicals have recently been identified as being able to

damage developing brains in fetuses and little children. By adding these six chemicals to the

ones already identified, there are now a dozen known toxins that affect developing brains. Some

of these chemicals have already been banned in Europe.

Berman (2014) claims that pediatricians are recognizing the links between toxic

chemicals and brain disorders. Berman states that Dr. Landrigan, a pediatric doctor, claims that

chemical exposure has become a serious threat and lists many problems that result from early

brain injuries, such as short attention spans and problems with behavior that children do not seem

to outgrow. Additionally, the amount of chemicals that experts suspect is causing problems in the

brain development of children continues to rise. These include the chemicals found in cleaning

products (Berman).

Chemical exposure in the air can happen both outdoors and indoors. This includes homes

and schools, according to Cometto-Muñiz and Abraham (2015). In a study conducted by

TOXIC CHEMICALS AND LEARNING DISABILITIES 4

Cometto-Muñiz and Abraham, 152 chemical groups were found in various schools. Some recent

studies have shown a link between toxic chemicals and learning disabilities as well as ASD,

ADHD, and dyslexia. Patisaul (2017) states that neurodevelopmental disorders (NDDs) are

caused by multiple factors, but increasing evidence is showing that exposure to chemicals is one

of them. Heilbrun et al. (2015) state that children are particularly susceptible to negative effects

from exposure to toxins. Several studies reveal a link between exposure to chemicals and NDDs.

LaKind et al. defines NDDs as brain-related disabilities that have an effect on the behavior,

memory, or learning ability in children. LaKind et al. lists ADHD, dyslexia, and ASD as NDDs.

Some schools have begun to implement changes to help reduce the presence of toxic

chemicals in their school buildings (Environmental Protection Agency, 2018a). Plymouth Public

Schools is one example. Plymouth Public Schools have changed over to all green cleaning

products (Plymouth Board of Education, n.d.). The Plymouth Board of Education states their

purpose for implementing this initiative is to protect their custodial staff as well as students and

faculty. They wish to prevent sicknesses that are linked to the chemicals found in cleaning

supplies as well as to protect the environment. No parents, teachers, or students are allowed to

bring in any cleaning, deodorizing, sanitizing, or disinfecting products. Only products that pass

the green test are allowed to be used, and janitors are trained on how to use them. Janitors are

also aware of products that are strictly prohibited in the schools. Among the chemicals listed are

aerosols of any kind and phthalates.

In addition to chemical exposure in the air, chemicals can be ingested through food and

beverages (Judge et al., 2017). Judge et al. argues that chemicals may have effects on the nervous

system. Examples of these effects are stimulation or depression of brain activity. Discovering the

link between chemical exposure and the functioning of the brain offers knowledge to those in

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medical and scientific positions as well as those who make and change health protective policies.

Expanding research on chemical exposure is one way to improve the overall protection of health.

Statistical Numbers of Learning Disabilities

One in every six children in America is reported as having developmental problems,

which includes learning disabilities, ASD, ADHD, and more. Those numbers are up 17%

compared to ten years ago (Bennett et al., 2016). Arbuckle, Davis, Boylan, Fisher, and Fu (2016)

report that back in 2006, a little over three percent of Canadian children from age five to 14 had

learning disabilities. According to Chopra, Harley, Lahiff, and Eskenazi (2014), learning

disabilities and ADD are the most commonly diagnosed neurobehavioral disorders among

children, affecting five–12% of children in the United States who are school-aged. According to

Lanphear (2015), mental disorders and learning disabilities are currently two of the most

predominant illnesses among children. A little over seven percent of children in the United States

are projected to have a learning disability reported by their parents, and 13% are projected to

have mental disorders such as ASD and ADHD.

Autism Spectrum Disorder

Lai, Lombardo, and Baron-Cohen (2014) define autism as a set of varied

neurodevelopmental conditions that are categorized by social complications and problems

communicating at a young age. Additionally, repetitive behaviors are typically present. ASD is

world-wide, affecting a total of one percent. Those with autism have nonconforming cognitive

profiles, including weakened social understanding and discernment. Additionally, those with

autism have difficulty making decisions and processing information.

ASD now affects two out of every 100 children in the United States, according to

Heilbrun et al. (2015). Lanphear (2015) reports an increase of 123% from 2002 to 2010 among

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children who were eight years old. ASD is more prevalent in young males compared to females.

Although awareness of ASD has increased and children are being diagnosed at earlier ages, there

is still no explanation for the increase in these numbers. Heilbrun claims that unknown factors

account for two-thirds of the increase in ASD in the last 30 years. According to Patisaul (2017),

genetics may only be responsible for about 50% of the risk, and that environmental factors

account for the rest. Studies of ASD in twins show that heredity only contributes to about 30% to

40%. According to Pearson et al. (2016), there is a connection between transcriptional changes in

the brain and ASD.

Attention Deficit Hyperactivity Disorder

Thapar and Cooper (2016) define ADHD as an NDD that weakens attention span and

increases hyperactive and impulsive behavior. Possible symptoms of inattention include not

paying attention to details or making thoughtless errors; having a hard time staying on task and

paying attention; not listening or understanding even when spoken to directly; not following

through on tasks, not completing assignments at school, chores at home, or job requirements; not

being able to organize; avoiding responsibilities that require mental energy; losing things needed

to complete responsibilities; becoming distracted easily; and forgetfulness. Possible symptoms of

hyperactivity or impulsivity include fidgeting or tapping of hands or feet; squirming; getting up

when expected to remain seated; running or climbing during inappropriate times; inability to be

quiet; always moving; talking in excess; blurting out answers before questions have been

completely asked; inability to wait for a turn; and interrupting. These symptoms typically

continue beyond childhood, especially inattention symptoms. However, Thapar and Cooper

claim that some adults do overcome all symptoms.

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According to Heilbrun et al. (2015), ADHD affects close to 10 of every 100 children

between the ages of four and 17, which is over five percent higher than the last decade. Lanphear

(2015) reports an increase of 22% from 2003 to 2007. Hu et al. (2017) claim that there is no cure

for ADHD, and that it “shows high comorbidity with oppositional defiant disorder (ODD)” (p.

375). In addition, children with ADHD are more likely to be challenged in school, both

academically and socially.

Greenblatt and Gottlieb (2017) state that children who reside in big cities are diagnosed

more often with ADHD than children who do not live in big cities. Greenblatt and Gottlieb claim

the reason these numbers are different is because of the pollution exposures in big cities. In

addition, Greenblatt and Gottlieb state that children who live in poverty are diagnosed twice as

often as those not living in poverty. According to Lanphear (2015), young males are 2 1/2 times

more likely to be diagnosed with ADHD than young females. Additionally, children with ADHD

typically have learning disorders as well. Patisaul (2017) states that genetics predict only tiny

increases in ADHD symptoms, stressing how the risk of ADHD comes from multiple factors.

One of those factors includes the environment. Park et al. (2014) states that genes accounts for

about 75% of ADHD development, and other factors, such as the environment, account for 25%

of ADHD development.

Dyslexia

Norton, Beach, and Gabrieli (2015) define dyslexia as a problem in reading words

accurately and/or fluently. Norton et al. state that dyslexia affects as many as 12% of children.

Dyslexia has been diagnosed in every culture world-wide and has comorbidity with ADHD

(Peterson & Pennington, 2012). There are several negative consequences of dyslexia. Norton et

al. state that children with dyslexia have lower educational achievements and self-esteem. Also,

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children with dyslexia do not read outside of school as much as children who do not struggle

with dyslexia. Less reading outside of school results in a big hole in reading skills.

According to the Yale Center for Dyslexia and Creativity (2017), dyslexia is quite

common and affects 20% of the population. Dyslexia represents up to 90% of all learning

disability diagnoses. The research on dyslexia indicates there are brain differences between those

diagnosed with dyslexia and those without. This research explains why fluent reading is such a

challenge for those with dyslexia.

Dyslexia Help at the University of Michigan (2018) states that the causes of dyslexia are

still unknown, but experts believe there is a genetic factor. Additionally, scientists believe

neurological irregularities in the brain make reading and comprehension a real challenge for

children with dyslexia. At one point in history, it was believed that males struggled with dyslexia

more than females, but that myth has been proven false.

Chemical Statistics

According to Patisaul (2017), there are close to 90,000 chemicals in our environment

today. While not all of these chemicals pose dangerous threats, a large number of them are in the

human body. In recent studies, more than 300 chemicals were found in the blood of fetal-cords

as well as breast milk. These results show that babies are born already exposed to many

chemicals. While some chemicals have been the subject of research studies for years, most of

them have never been tested for their toxicity. In fact, Patisaul claims it is only in rare cases that

chemicals get formally tested for toxicity in the United States. Testing for neurodevelopmental

effects or the disruption of the endocrine systems happens even less.

Patisaul (2017) states that the system used to regulate chemicals in the United States

evades the restriction of toxic chemicals currently available to consumers because removal of

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them requires unmistakable evidence of adverse results. Unfortunately, results showing delays in

language, low IQs, or various types of learning disabilities do not produce such evidence.

Additionally, when considering restrictions, priority is placed on the financial benefits of using

certain chemicals over their potential long-term harm. Patisaul adds that even in instances where

toxic chemicals have been restricted, the process took longer than necessary. Lanphear (2015)

argues that the influence of chemicals on brain disorders is often unnoticed, undervalued, or

discounted. Lanphear believes the reason for that is because the effects are elusive. Lanphear

also argues that having no official process to assess chemicals blocks efforts of prevention. The

impact chemicals have on the brain should not merit less attention than carcinogens, which have

been shown high priority in the past.

According to Steinemann (2018), when a product’s ingredient label lists fragrance, it

usually means there is a mixture of up to several hundreds of chemicals. Those chemicals that

make up the fragrance are not required to be listed on the product’s label. They do not have to be

listed on the data safety sheet either. Lastly, products containing fragrances usually release

dangerous contaminants into the air. One such contaminant is formaldehyde.

Heilbrun et al. (2015) state people spend most of their day inside their homes, offices,

and schools. In the last 70 years, the types and levels of volatile organic compounds (VOCs)

found inside buildings have increased at a significant rate. Unfortunately, up to 30% of those

people who spend most of their day inside are intolerant to chemicals, even at low exposure

levels. Chemically intolerant individuals report multiple symptoms when exposed to chemicals,

and their symptoms often involve the central nervous system.

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Chemicals and Learning Disabilities

According to Bennett et al. (2016), children in the United States have a high risk of

developing disorders such as ASD, ADHD, and other disabilities. There could be several causes

of these disorders as they tend to be complex in nature. Patisaul (2017) states that ASD and other

neurological disorders typically result from a combination of genetics and environmental

connections, including exposure to chemicals. However, Patisaul adds that discovering which

chemicals, which genes, and which have interactions presents a problem. Some studies have

found the chemicals that pose the greatest threat, but more research is needed.

Heindel et al. (2016) states that, at times, exposure to environmental chemicals can cause

normal fetuses to be vulnerable to diseases and dysfunctions later in their lives. Certain

environmental chemicals, called EDCs (Kajta & Wojtowicz, 2013), can regularly interfere with

endocrine development (Heindel et al.). Heindel et al. goes on to say that it depends on whether

one’s endocrine system is chemically sensitive. Timing also plays a role. Although the timing for

sensitivity often happens in utero, it can also happen during childhood and into young adulthood.

According to Kajta and Wojtowicz, EDCs interact with the “hypothalamus-pituitary-thyroid

gland axis” (p. 1633), which is vital for the brain to grow and function correctly. Lastly, EDC

exposure has been linked to problems with behavior as well as learning disorders (Scinicariello

& Buser ,2016).

According to Arbuckle et al. (2016), learning disabilities, ADHD, and other disorders that

affect development in children, not only burden families, but also schools. Bennett et al. (2016)

state the costs to educate children with learning or developmental disabilities is double the cost

to educate children without learning disabilities. Children with developmental disabilities can

sometimes become antisocial, do not always do as well academically, and often abuse drugs and

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get into trouble with the law as they grow older (Arbuckle et al.). Arbuckle et al. stress the

importance of studying not only the genetic factors of ADHD, but also the environmental factors.

The possibility of chemicals playing a role in the development of problematic behaviors in

children should not be ignored. Many studies have already been conducted on the probable

relationship between them. Arbuckle et al. adds that young children’s brains are significantly

more sensitive to chemical exposure than adult brains, and therefore, the risks of chemical

exposure should be thoroughly examined. Bennett et al. claims that the prevention of exposure to

toxic chemicals is possible.

In 2015, according to Bennett et al. (2016), advocates for children’s health, medical

professionals, and scientists made a call to action to reduce chemical exposure to children.

Bennett et al. listed the toxic chemicals that they believe increase the risk of neurodevelopmental

disorders. Some chemicals are commonly found in consumer products as well as the

environment. Other chemicals are those that are often exposed to children and pregnant women.

Bennet et al. add that most industrial chemicals and those found in common products do not go

through much testing to see if there are potential health risks or risks of developmental disorders.

Therefore, to aid in the reduction of developmental disorders and learning disabilities, exposure

to chemicals needs to be reduced, if not completely eliminated. Bennett et al. suggests a redesign

of the chemical assessments, as well as new ways of monitoring chemical exposure, in order to

protect the development of children’s brains. In addition, Bennett et al. believe that the reduction

of chemical exposure will lower the occurrence of learning disabilities and enable more children

to succeed.

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Indoor Air Quality

It is common knowledge that pollution in the air outside sometimes adversely impacts

health, but according to the EPA (2018b), the air indoors has just as much of an impact on

health. The EPA states that the level of contaminants indoors is usually two to five times higher

than the outside levels. However, indoor pollution can be up to 100 times as high. Since the

average person spends 90% of their lives inside, this is a big concern. The EPA adds that

managing the quality of indoor air involves controlling airborne contaminants, introducing and

distributing outdoor air effectively, and maintaining satisfactory temperatures inside. The reason

that temperature and humidity should be considered is that they are among the many things that

influence indoor levels of pollutant. Additionally, outdoor air quality should be considered

because outside air can still enter schools through entryways, windows, and airing systems. This

means that the maintaining of school grounds and transportation also influence the quality of

indoor air.

According to the EPA (2018b), recent studies have classified poor indoor air quality as

one of the top five risks to health. Air quality inside is vital to maintaining healthy environments

indoors, and can aid schools in their quest to educate children. When indoor air quality is poor,

health problems increase, not only among students, but in faculty and staff. Illnesses like

coughing, eye problems, headaches, allergies, nausea, dizziness, and even carbon monoxide

poisoning can happen. Asthma and other breathing problems can be triggered by poor indoor air

quality as well. The EPA claims that more children miss school because of asthma than any other

sickness. Poor indoor air quality leads to absentees and can affect students’ comfort and ability to

perform. Faculty and staff are affected as well and may not perform to their potential. Since

children are still developing, they may be more vulnerable to toxic exposures compared to adults.

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Children take in more air and eat more than adults. Thus, the quality of indoor air in schools is a

great concern. Maintaining good air quality inside of schools is vital for the safety of students,

teachers, and staff.

Bisphenol A and Phthalates

Arbuckle et al. (2016) state that certain chemicals, such as bisphenol A (BPA), lead, and

phthalates may be contributing factors in behavioral problems and learning disabilities in

children. Likewise, Lanphear (2015) states that BPA and phthalates may increase the risks for

ADHD and behaviors related to ADHD. BPA can be found in refillable water bottles and can be

used on the inside of metal cans that store food and beverages. According to Kajta and

Wojtowicz (2013), BPA, even in low doses, may cause inadequate “methylation of specific gene

regions in the young brain and impair hippocampal neurogenesis across generations” (p. 1634).

Kajta and Wojtowicz add that there is a solid connection between BPA exposure in pregnant

women and amplified locomotor movement and aggression among children. Phthalates and BPA

partly disrupt hormones, either estrogenic or thyroid, according to Lanphear (2015), and disturb

neurons in the prefrontal cortex. This disturbance recognizes the theory that ADHD is caused by

a lack of dopamine in the prefrontal cortex. Lanphear adds that BPA is connected to anxiety and

hyperactive behaviors.

Patisaul (2017) argues that there is a link between risks of ASD and phthalates.

Phthalates can be found in a wide variety of consumer products such as fragrances, cosmetics,

personal care products, and adhesives. Park et al. (2014) claim that phthalates are produced at

such a high rate and are so commonly used, that people are exposed to them on a daily basis,

either through food, air, or their skin. Hu et al. (2017) state that many research studies have

provided evidence that children expel higher concentrations of phthalates than adults do.

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Additionally, studies show phthalates may affect the nervous system. In studies conducted on

animals, when exposed to certain phthalates, cell proliferations were inhibited, cell

differentiation was promoted, and “cell apoptosis in neurocytes” (p. 376) was induced.

Furthermore, exposure to phthalates among rodents showed an association with hyperactivity,

depression, anxiety, and inability to socialize.

Bennett et al. (2016) state that certain chemicals, including phthalates, disturb the

endocrine system. Brown (2018), a medical doctor, adds that the chemicals found in most

household cleaning agents can harm the endocrine system, along with causing many other

adverse health problems. These chemicals raise concerns because they affect the hormones that

are vital to the development of healthy brains. Chopra et al. (2014) state that phthalates have

been shown to affect the neurodevelopment of rats. Other studies with humans have shown

positive associations of phthalates and ADHD, such as the one conducted in Korea on 261

children ranging from age eight to 11 years of age.

According to Park et al. (2014), research studies revealing evidence of chemical

exposures and the adverse effects they have on the development of children are becoming more

and more common. Park et al. states that phthalates, which disrupt the endocrine system, affect

the growth of fetuses, have negative effects on reproduction and puberty, and affect

neurodevelopment. According to Verstraete et al. (2016), exposure to phthalates has been

directly linked with ADHD. Verstraete et al. hypothesized that the presence of phthalates in the

pediatric unit of a hospital contributes to prolonged ADHD symptoms. Some research studies

show that some phthalates at high levels adversely effects the behavior of mice. In human

studies, phthalate exposure in pregnant women is connected to problems at birth, neurological

issues in babies, social problems for children, and more. Park et al. claim that recently, studies

TOXIC CHEMICALS AND LEARNING DISABILITIES 15

have shown connections between phthalate concentrations, ADHD, and the ability to make

decisions. Some studies in animals show that phthalate exposure could be responsible for

hyperactive and impulsive behavior in lab rats. The behavior that these lab rats exhibited were

very similar to the symptoms exhibited by children with ADHD. Lastly, Park et al. state that

recent studies have shown symptoms of ADHD in children whose mothers were exposed to

phthalates during their pregnancies.

Disinfectants, Solvents, Deodorizers, Air-Fresheners, and other Fragrances

Feldscher (2014) states solvents are associated with aggression and hyperactive behavior.

According to Brown (2018), many deodorizers commonly used in public restrooms, and possibly

in some schools, release VOCs into the air. In addition to causing health problems in the lungs,

throat, eyes, liver, and skin, some VOCs cause the brain to deteriorate. Brown adds that many air

fresheners release phthalates into the air as well. Lanphear (2015) states that pollutants in the air

may increase the risks for ASD, ADHD, and behaviors connected to ADHD. Steinemann (2018)

states that products containing fragrance release toxins in the air that can damage one’s health.

According to Patisaul (2017), recent assessments link the risk of ASD to numerous chemicals,

including solvents, air pollutants, fragrances, and more. Unfortunately, manufacturers of

fragranced products are exempt from listing ingredients on the labels of their products

(Steinemann).

Caffeine and Aspartame

Caffeine

Ioannidis, Chamberlain, and Müller (2014) state that caffeine is one of the most common

substances on the planet. About 50% of psychiatric patients consume it regularly. Ioannidis et al.

claim that people have been misusing caffeine for hundreds of years. There is no doubt about the

TOXIC CHEMICALS AND LEARNING DISABILITIES 16

side effects of caffeine, such as harmful effects on sleep and on circulatory restrictions. Some

have demanded for legal action to control the use of caffeine with no success. Despite the

warnings of caffeine, many people consume it on a regular basis. Most of them are not aware

that they are ingesting doses high enough to alter their emotions, behavior, and cognition.

According to Ioannidis et al. (2014), teenagers who have ADHD are twice as likely to

drink caffeinated drinks than their peers who do not have ADHD. Additionally, many people

with ADHD consume high enough doses of caffeine to affect their cognition, how alert they are,

and their symptoms of ADHD. Research has shown that the consumption of caffeine actually

makes the symptoms of ADHD more severe. Girls with ADHD self-reported violent behaviors

and conduct problems when consuming caffeine.

Aspartame

Aspartame is an artificial sweetener produced chemically and typically found in

thousands of products such as foods, medicine, desserts, cereal, vitamins, and drinks, especially

diet drinks and powdered drinks (Choudhary & Pretorius, 2017). Aspartame is up to 300 times

sweeter than sucrose and has a clean, bitter-less taste. It costs a lot less than sugar, which makes

it attractive to producers. Safety concerns connected to aspartame consumption include possible

toxicity from aspartame metabolites, including formaldehyde. When aspartame is consumed, gut

enzymes break it down into phenylalanine, which “can cross the blood–brain barrier” (p. 719),

aspartic acid, and methanol. Phenylalanine is broken down even further in the liver and converts

into several enzymes before ultimately converting into dopamine, norepinephrine, and

epinephrine. Moreover, increases of phenylalanine and aspartic acid in plasma concentrations

result in larger transports of amino acids inside the brain, which modifies the brain’s

TOXIC CHEMICALS AND LEARNING DISABILITIES 17

neurochemical structure. Phenylalanine has been shown to make neuroendocrine changes in the

brain.

Choudhary and Pretorius (2017) state that aspartame affects the “cerebral cortex,

hypothalamus, and hippocampus” (p. 721). These areas of the brain assist recall and the ability to

make decisions. Studies have shown that aspartame is toxic to the brain, even with the approved

amount. High doses of aspartame, as well as recommended doses were shown to adversely affect

learning and recall. Because of recent concerns, the PepsiCo company banned aspartame from its

products (Paolini, Vivarelli, Sapone, & Canistro, 2016).

Lindseth, Coolahan, Petros, and Lindseth (2014) state that some studies show aspartame

adversely affects cognition where as others prove otherwise. Lindseth et al. also reports mixed

results pertaining to aspartame and headaches, depression, and mood. However, after conducting

their own study, results showed scores were much better for participants after they had consumed

low doses of aspartame compared to when they had higher doses. Two of them experienced

substantial adverse effects in cognition after ingesting high amounts of aspartame. A different

pair of participants experienced memory impairment. All participants experienced depression

with high aspartame consumption, and three of them experienced clinical depression. Lindseth et

al. conclude that aspartame had an effect on neurobehavior.

Recent Research Studies on Chemical Exposure and Learning Disabilities

In a study conducted by Heilbrun et al. (2015), results indicated that chemically intolerant

women are more likely to give birth to children who will develop ASD or ADHD compared to

women who are not intolerant to chemicals. In addition, the results of the study showed that

children with ASD or ADHD who also had chemically intolerant mothers were more sensitive to

TOXIC CHEMICALS AND LEARNING DISABILITIES 18

the odors emitted from chemicals. Those same children are reported to have more allergies,

infections, and drug reactions than children whose mothers are not chemically intolerant.

Arbuckle et al. (2016) conducted a study in which they examined the possible

relationship between chemical exposure and behavior in children. The researchers used a

questionnaire that measured emotions, ADHD symptoms, and a score that measured total

difficulties. They compared scores of children with normal scores of children who scored

borderline or abnormal. Additionally, blood and urine samples were taken. Considerations in this

study were gender, medication, and whether children had ADHD, dyslexia, or other diagnoses.

The results from this study showed that behavior in some of the children was significantly

connected with the presence of BPA, lead, and phthalates in their urine samples. Arbuckle et al.

add that other studies similar to theirs have shown positive relationships between chemicals and

ADHD symptoms.

Chopra et al. (2014) conducted a study in the United States to investigate the relationship

between phthalate metabolite levels in urine samples and learning disabilities. The children in

this study ranged from age six to 15 years old. One hundred twelve children were reported by

their parents to have ADD diagnoses, 173 children were reported by their parents to have

learning disabilities, and 56 children were reported by their parents to have both. Considerations

in this study were gender, race, age, income, blood lead, and exposure to prenatal smoking. The

results from this study suggest associations between phthalates and ADD and learning

disabilities, especially among females.

Hu et al. (2017) conducted a study in China to examine whether exposure to phthalates

was linked to ADHD. Hu et al. recruited 225 children with ADHD and 225 children with no

ADHD diagnosis. The children were between six and 13 years of age and were drafted from two

TOXIC CHEMICALS AND LEARNING DISABILITIES 19

different schools as well as a children’s hospital that specializes in behavioral psychology.

Surveys were taken, and urine was collected and analyzed. Results from this study showed that

that higher concentrations of certain phthalates were linked to higher ADHD and ODD diagnoses

probabilities. Likewise, high concentrations resulted in symptoms of inattention symptoms. High

concentrations were also linked to problems with attention, aggression, externalization,

depression, and internalization. It is important to note that results indicated that there were

significant links to behavior problems among males whereas females were more withdrawn.

Steinemann (2018) studied the effects of fragranced products on those with asthma and

those who do not have asthma. In this study, Steinemann characterized fragrances into six

categories, including air fresheners, deodorizers, and cleaning supplies. After exposure to various

fragranced products, those with asthma, and those who do not have asthma, reported many

adverse effects. Some of the adverse effects included migraines asthma attacks, problems

breathing, problems with their skin, and cognitive problems. The cognitive problems included

having a difficult time focusing, thinking, and recalling. Results from this study showed health

problems occurring when subjects were placed in a room that had just been cleaned with

fragranced cleaning products and being around others who were wearing perfumes, colognes,

and other types of scented products.

In an experiment by Judge et al. (2016), six teenagers came up with a test to evaluate the

behavior of the planarian flatworm, which served as the model. The group of teens observed the

worm before, during, and after chemical exposure. The teens believed that exposure to chemicals

would affect the worm’s nervous system, thus altering its behavior. The two chemicals used in

this study were caffeine and aspartame, an artificial sweetener found in most diet drinks. Results

TOXIC CHEMICALS AND LEARNING DISABILITIES 20

of this study showed that caffeine altered the worm’s behavior and the aspartame significantly

altered the worm’s behavior.

Park et al. (2014) conducted a study to examine concentrations of phthalate metabolites

in the urine of children with ADHD. This study was conducted in Korea with 179 children who

were chosen with the help of a hospital psychiatry unit. The children in this study were between

the ages of six and 15 years of age. There were 147 boys and 32 girls who participated in this

study. Urine samples were collected and the continuous performance test (CPT) was

administered to see if there were any correlations. The CPT measures inattentiveness and

impulsive behaviors in children and is used more often than any other test. For some children

with high concentrations, there were more errors and varying response times. Results from this

study show that there could be a possible connection between concentrations of phthalate

metabolites and attention problems. Park et al. conclude that the presence of phthalate

concentrations in urine, especially at high levels, might be a vital factor in raising the risks of

ADHD diagnoses.

Pearson et al. (2016) sought to pinpoint chemicals that mimic ASD transcriptionally in

their study. As a result of this study, eight chemicals were discovered to fit the criteria. Most of

them were pesticides and fungicides. The chemicals discovered caused microtubule disruption

and encouraged the production of free radicals. The process used in this study was a comparison

of “gene expression profiles of cortical cell cultures with expression data from human brain

disorders” (p. 6). Mice were used in this study because, according to Pearson et al., cortical

cultures of mice model human’s cortical cultures.

In a pilot study conducted by Quirós-Alcalá et al. (2016), the presence of seven chemicals

were tested in 14 child care facilities in the District of Columbia. Quirós-Alcalá et al. state that

TOXIC CHEMICALS AND LEARNING DISABILITIES 21

all seven of the chemicals had been linked to adverse health effects. Quirós-Alcalá et al. used

surveys to determine the children’s health history. Additionally, the surveys inquired as to what

kinds of cleaning took place in the centers. Considerations in this study were locations,

especially when considering how close they were to other contaminants. This study revealed

significant levels of chemicals, especially VOCs, in all the child care centers.

In a simulated study conducted by Joe Allen, assistant professor of exposure-assessment

sciences at the Harvard Chan School, Walsh (2018) reports that the mental function of

participants was affected significantly in all areas. The nine areas tested were focus, data usage,

and strategy. Participants scored 97% higher in a verified green building versus the building that

had the presences of VOCs.

In a longitudinal study conducted by Verstraete (2016), whether the presence of

phthalates contributed to long-term ADHD was tested in 100 healthy children and 449 children

who were patients in a pediatric unit of a hospital. Phthalate concentrations from plasma was

collected and measured. Four years later, those children were tested neurocognitively. Results

showed children had symptoms of ADHD as well as decreased coordination. The effects from

this exposure to phthalates explained 50% of the ADHD symptoms in former patients of the

pediatric care unit. In summary, Phthalate exposure while in pediatric care was significantly

linked to ADHD symptoms observed in patients four years after their treatment.

Del-Ponte et al. (2016) conducted a study in Brazil to assess whether there is a link

between the intake of caffeine during pregnancy by mothers and 11-year-old children diagnosed

with ADHD. During this study, 3485 children were analyzed. The results showed no significance

connections between caffeine consumption during pregnancy and ADHD in 11-year-old

children.

TOXIC CHEMICALS AND LEARNING DISABILITIES 22

Call to Action

The financial cost of toxic chemicals and their impact on the brain is assessed above $70

billion in the United States each year (Lanphear, 2015). However, $70 billion does not include

the effects of all chemicals. Furthermore, it does not include the cost it takes to research. More

importantly, it does not include the cost of children’s suffering, the effects chemicals have on

their ability to function each day of their lives, and the adjustments and arrangements that

parents, teachers, and others make for them (Lanphear). According to Berman (2014), specialists

are requesting restrictions on the use of toxic industrial chemicals, which they claim are

producing a “silent pandemic of brain disorders” (p. 2) all over the world. Researchers are

begging for action to take place as more neurotoxins have been recognized but continue to have

no official regulations.

In-Depth Research

Heindel et al. (2016) call for more research regarding environmental chemicals and links

to diseases and dysfunctions. Heindel et al. suggest taking a combined approach by integrating

whether environmental factors play a role in the development of disease in animals as well as

humans. Heindel et al states this will provide better understanding of how chemicals might cause

vulnerability to diseases and dysfunctions. Additionally, Heindel et al. suggest research that

begins at birth and examines not only nutrition but things that disrupt the endocrine system.

Heindel et al state that this type of research will provide the evidence needed to begin

interventions against environmental stressors. Lastly, Heindel et al. calls for an extensive list of

diseases and dysfunctions that are known to be affected by environmental stressors.

TOXIC CHEMICALS AND LEARNING DISABILITIES 23

World-Wide Prevention

Feldscher (2014) states world-wide prevention is necessary to control the use of

chemicals in order to protect the developing brains of children. Feldscher recommends testing of

these chemicals for potential adverse health effects as a requirement for manufacturers. Heilbrun

et al. (2015) claim that making changes in the home environment will help children with ASD

and ADHD. However, changes in the home can only help so much. Those children might still

attend schools that expose them to toxins. Lanphear (2015) suggests improving the EPA’s ability

to make the standards regarding the evaluation of how chemicals affect brain function. In

addition, a monitoring system should be created and funded.

According to Berman (2014), some professionals are proposing countries to pass new

laws requiring the testing of all chemicals before they are put on the market. Chemicals should

be tested much in the same way that drugs are tested. Berman claims that identifying possible

brain-damaging chemicals is not only possible, but rather simple. The methods to test these

chemicals are already in place. The only thing missing is the official decision to make the testing

a requirement. Another call to action would be to make the results of these tests available to the

public.

Medical Professionals

According to Heindel et al. (2016), sometimes the effects of environmental stressors do

not show up at birth, but that does not mean that they will not develop later in one’s life. Heindel

et al. states that medical professionals need to keep this in mind. Also, even when the effects of

environmental factors are found early in one’s life, sometimes the effects are so small that

medical professionals do not take them seriously. Heindel et al. calls for this to change and

claims that small detections usually set the standard for greater risks of diseases and dysfunctions

TOXIC CHEMICALS AND LEARNING DISABILITIES 24

later on. Heindel et al. suggests medical professionals change their focus to prevention in infants

and young children instead of waiting years later to treat adults. Heindel et al. list several

scientific groups who have made their own calls for action regarding this matter. Among them

are “The Endocrine Society, the American College of Obstetricians, the American Society of

Reproductive Medicine, the Royal College of Obstetricians and Gynecologists, the European

Society for Pediatric Endocrinology, and the United States Pediatric Endocrine Society” (p. 22).

School Administration

School administrators should look into more natural ways of cleaning, should eliminate

the usage of air fresheners, should utilize hand soaps that are free of toxic chemicals in the

bathrooms, and should require teachers and staff to refrain from wearing perfumes and cologne.

Brown (2018) states there are many companies offering toxic-free cleaning supplies, and if those

are not in the budget, effective cleaners made from more natural ingredients can be made quickly

and easily. Items such as white vinegar, salt, baking soda, essential oils, lemon juice, peroxide,

alcohol, and corn starch are common staples that Brown lists in his homemade cleaning

alternatives section.

The EPA (2018a) recommends that schools switch to more green cleaning products as the

most common cleaning products contain chemicals that can cause negative health effects.

Another suggestion by the EPA is to clean buildings when students are not present. The use of

products without fragrance is also suggested. Patisaul (2017) claims the results of studies that

link exposure to chemicals and neurodevelopmental problems demands more attention by

officials. Health concerns for children should be priority in assessing potential chemical risks.

Since chemicals such as caffeine and aspartame have been shown to alter behavior in the

flatworm (Judge et al., 2017), schools should consider removing sodas and other caffeinated

TOXIC CHEMICALS AND LEARNING DISABILITIES 25

drink machines from their campuses and replacing them with bottled water. Students should be

allowed to bring bottles of water into the classrooms and water fountains should be placed near

classrooms for easy access. Although caffeine and aspartame and their effects on learning

disabilities were not examined in the experiment by Judge et al., the altering of behavior may

trigger hyperactive behavior in children with ADHD. According to the Centers for Disease

Control and Prevention (2017), ensuring students have access to water provides them with a

healthier alternative to other drinks filled with sugar and chemicals. Additionally, encouraging

the consumption of water helps students to stay hydrated, which may help brain function.

Limitations

Studies that rely on observation are limited “in their ability to infer causal associations”

(Lanphear, 2015, p. 221). One reason is because the exposures are not assigned at random. Also,

some studies did not consider other factors occurring within the home or nurturing factors like

breastfeeding. Some studies did not consider secondhand smoke or other toxins in the

environment. Most studies did not consider the psychopathology of the parents. These limitations

are often used as an excuse to prevent steps to control toxins in the environment even though the

evidence is persuasive from both animal and human studies (Lanphear, 2015). Park et al. (2014)

state that these types of studies are limited because causal inferences are not possible. Further,

more in-depth research using a different approach is needed to discover causality. In addition,

some of these studies only recruited children with ADHD, but did not recruit any children

without ADHD. Research studies with no control groups do not provide as much validity. Lastly,

some of these studies utilized small sample sizes and could possibly produce more validity with

larger sample sizes.

TOXIC CHEMICALS AND LEARNING DISABILITIES 26

Criticism of the Literature and Research

LaKind et al. (2017) state that animal testing to retrieve date on toxicity is decreasing,

and therefore, human testing is likely to increase, especially with the consistent increase in

published articles pertaining to environmental toxins. In the last 30 years, the number of

publications has increased from less than 1,000 to more than 11,000, and that number keeps

rising. Because of this increase, Lakind et al. believe it is necessary to assess the research and

reviews being written on the subject. They sought to review relevant literature and research

studies in order to provide objective assessments, including both limitations as well as strengths

in the available research. These types of evaluations typically influence recommendations for

changes in public health and can lead to decision making in environmental health. Lakind et al.

state they only found 74 reviews that fit their four areas of qualifications: studies that could be

duplicated, literature reviews that contained structured assessments of available data, literature

that was consistent, and literature that provided potential biases. LaKind et al. claim that none of

the reviews they assessed met all four criteria areas. Four of the reviews met half of the criteria

and six of them met one of the four criteria. LaKind et al. conclude that there is no existing

literature that provides enough proof to support changes in public health.

Conclusion

In recent years, it has become evident that environmental chemical exposures are

possibly linked to diseases and disabilities, including learning disabilities, ADHD, ASD, and

dyslexia. Developing studies show that other global chemicals might be toxic. There is no

denying the effects that toxins have on the growing brain. Chemical exposure is happening to

children on a daily basis and begins while they are in the womb and continues throughout their

lives. Not only does exposure to chemicals happen outside, but happens indoors as well. The air

TOXIC CHEMICALS AND LEARNING DISABILITIES 27

quality inside most buildings is not only unhealthy, but much worse than the air quality of

outdoor air. Schools are no exception. Studies have shown a strong connection between chemical

exposure and learning disabilities as well as ADHD, ASD, and dyslexia. Although genetics plays

an important role in the risks of these disorders, environmental chemical factors are believed to

be contributing to the rising numbers.

Some schools have begun to implement changes to reduce toxic exposure to their

students, staff, and faculty, but more studies are needed to raise enough awareness to convince

other school administrations to do the same. With the numbers of ADHD, ASD, dyslexia, and

other learning disorder diagnoses rising every decade, more research needs to be done to

discover the causes, so prevention can be implemented. Stricter laws could be made so that all

chemicals are required to be tested for toxicity. Additionally, all chemicals should be required to

be tested for neurodevelopment effects and endocrine system disruption.

With more people spending most of their lives inside of buildings, indoor air quality

should become a higher priority world-wide, especially the air quality of school buildings where

children with growing brains spend most of their days. Although the financial cost to research

this more in-depth is high, the cost of educating children with learning disabilities is also high.

That is not counting the other costs. Learning disabilities, ADHD, ASD, and dyslexia put

burdens on the students, their families, and their teachers.

With the recent research studies showing the possibility of toxic chemicals playing a role

in children's behavior and brain development, more in-depth research should become the highest

priority. Chemical exposure prevention is not impossible. More in-depth research could lead to

prevention world-wide and a change in the perspectives of medical professionals as well as

school administrators. These changes are needed so that all children can live up to their potential.

TOXIC CHEMICALS AND LEARNING DISABILITIES 28

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