Julia Riddell - Academia.edu (original) (raw)

Papers by Julia Riddell

Research paper thumbnail of Urinary Fluoride Levels Among Canadians and the Association Between Fluoride Exposure and Attention Deficit Hyperactivity Disorder

Fluoride has been identified as a developmental neurotoxin-a claim that is uncontested at high ex... more Fluoride has been identified as a developmental neurotoxin-a claim that is uncontested at high exposure levels, but remains debated at low exposure levels. In Canada, 39% of municipalities add fluoride to their drinking water at a recommended level of 0.7ppm. Exposure to fluoride has been linked with increased prevalence of attention deficit hyperactivity disorder (ADHD) in the United States and symptoms of inattention in Mexican children. This dissertation consists of one study examining the association between fluoride exposure and symptoms of ADHD in youth, and a second study examining the predictors of an individual's level of urinary fluoride. Study 1 used cross-sectional data on youth 6 to 17 years of age from the Canadian Health Measures Survey (CHMS, Cycles 2 and 3). Urinary fluoride concentrations were measured in spot samples and adjusted for specific gravity (UF SG , n=1877) and water fluoride concentrations were measured in tap water samples (n=980). We used logistic regression to test the association between fluoride exposure and ADHD diagnosis and linear regression to examine the relationship between fluoride exposure and the hyperactive-inattention subscale score on the Strengths and Difficulties Questionnaire (SDQ). UF SG did not predict ADHD diagnosis or SDQ score, whereas a 1 mg/L increase in tap water fluoride level was associated with 6.1 times higher odds of an ADHD diagnosis (95% CI = 1.60, 22.8) and a 1.5 increase in SDQ score for adolescents. Study 2 used data from Cycle 3 of the CHMS to examine factors that influence urinary fluoride levels in a sample of 1629 individuals aged 3 to 79 years. In the linear regression models, tap water fluoride level, community water fluoridation status, age, sex, BMI, smoking allowed in the home, and tea consumption were significant predictors of UF SG. Community water fluoridation and tap water fluoride were associated with higher levels of fluoride excretion and with an increased risk of ADHD symptoms and diagnosis among Canadian youth. These findings highlight the need to identify subgroups who may have especially high levels of exposure and to further investigate the potential for fluoride-mediated developmental neurotoxicity in populations with community water fluoridation.

Research paper thumbnail of Corrigendum to Association of water fluoride and urinary fluoride concentrations with attention deficit hyperactivity disorder in Canadian youth

Environment International

Research paper thumbnail of Cyberbullying in Canada

International Perspectives on Cyberbullying, 2018

Cyberbullying is a significant problem in Canada, with high prevalence rates that have remained s... more Cyberbullying is a significant problem in Canada, with high prevalence rates that have remained stable over the past decade (Boak et al. 2016; Craig et al. 2016). A number of highly publicized Canadian cases have underscored the significant implications of involvement in cyberbullying. For example, Amanda Todd, a 15-year-old from western Canada, was lured by a man who manipulated her to share intimate pictures of herself with him (BBC News 2014). When these pictures were posted to Facebook, Amanda was severely bullied by peers at school, causing her to change schools a number of times. She posted a video on YouTube that detailed her struggles with cyberbullying before taking her own life (BBC News 2014). Another young woman, Rehtaeh Parsons, had a photo of her sexual assault shared with peers via text messages (Gillis 2013). After

Research paper thumbnail of The Development of Self in Relationships: Youths' Narratives of Change Through a Residential, Wilderness and Family Therapy Intervention

Research paper thumbnail of Fluoride Exposure and Thyroid Function among Iodine Deficient Adults in Canada

ISEE Conference Abstracts, 2018

Background: Fluoride exposure has the potential to disrupt thyroid functioning, though adequate i... more Background: Fluoride exposure has the potential to disrupt thyroid functioning, though adequate iodine intake may mitigate this effect. This study is the first population-based study to examine the...

Research paper thumbnail of Urinary Fluoride Levels among Canadians with and without Community Water Fluoridation

International Journal of Environmental Research and Public Health, 2021

Drinking water is a major source of dietary fluoride intake in communities with water fluoridatio... more Drinking water is a major source of dietary fluoride intake in communities with water fluoridation. We examined the association between urinary fluoride adjusted for specific gravity (UFSG) and tap water fluoride levels, by age and sex, among individuals living in Canada. Participants included 1629 individuals aged 3 to 79 years from Cycle 3 (2012–2013) of the Canadian Health Measures Survey. We used multiple linear regression to estimate unique associations of tap water fluoride levels, age, sex, ethnicity, body mass index (BMI), use of fluoride-containing dental products, smoking in the home, and tea consumption with UFSG. UFSG concentration was significantly higher among participants who received fluoridated drinking water (mean = 1.06 mg/L, standard deviation = 0.83) than among those who did not (M = 0.58 mg/L, SD = 0.47), p < 0.01. UFSG increased over adulthood (ages 19 to 79). Higher UFSG concentration was associated with being female, tea drinking, and smoking in the home....

Research paper thumbnail of Better Relationships, Mental Wellness, and Self-Development: What Parents Expect from Residential Treatment for Their Struggling Youth

Journal of Therapeutic Schools and Programs

Parents often initiate treatment for their youth with substance use or mental health issues. For ... more Parents often initiate treatment for their youth with substance use or mental health issues. For this reason, parental expectations of treatment are helpful in considering the nature of parental engagement in the treatment process and possible barriers to treatment. The goal of this study was to better understand the expectations of parents who sought residential treatment for their youth. From 638 potential parent applications, 28 individual applications were randomly selected for in-depth qualitative analysis. The most frequently expressed expectation was for youth to have better relationships with their family and with peers. Implications for treatment program design, effectiveness, and evaluation are discussed.

Research paper thumbnail of Association of water fluoride and urinary fluoride concentrations with attention deficit hyperactivity disorder in Canadian youth

Environment International

Background: Exposure to fluoride has been linked with increased prevalence of attention deficit h... more Background: Exposure to fluoride has been linked with increased prevalence of attention deficit hyperactivity disorder (ADHD) in the United States and symptoms of inattention in Mexican children. We examined the association between fluoride exposure and attention outcomes among youth living in Canada. Method: We used cross-sectional data collected from youth 6 to 17 years of age from the Canadian Health Measures Survey (Cycles 2 and 3). Urinary fluoride concentration adjusted for specific gravity (UFSG) was available for 1877 participants. Water fluoride concentration measured in tap water samples was available for 980 participants. Community water fluoridation (CWF) status was determined by viewing reports on each city&#39;s website or contacting the water treatment plant. We used logistic regression to test the association between the three measures of fluoride exposure and ADHD diagnosis. Linear regression was used to examine the relationship between the three measures of fluoride exposure and the hyperactivity/inattention score on the Strengths and Difficulties Questionnaire (SDQ). Results: UF SG did not significantly predict ADHD diagnosis or hyperactive/inattentive symptoms. A 1 mg/L increase in tap water fluoride level was associated with a 6.1 times higher odds of an ADHD diagnosis (95% CI = 1.60, 22.8). A significant interaction between age and tap water fluoride level (p = .03) indicated a stronger association between tap water fluoride and hyperactivity/inattention symptoms among older youth. A 1 mg/L increase in water fluoride level was associated with a 1.5 SDQ score increase (95% CI: 0.23, 2.68, p = .02) for youth at the 75th percentile of age (14 years old). Similarly, there was a significant interaction between age and CWF. At the 75th percentile of age (14 years old), those living in a fluoridated region had a 0.7-point higher SDQ score (95% CI = 0.34, 1.06, p &lt; .01) and the predicted odds of an ADHD diagnosis was 2.8 times greater compared with youth in a non-fluoridated region (aOR = 2.84, 95% CI: 1.40, 5.76, p &lt; .01). Discussion: Exposure to higher levels of fluoride in tap water is associated with an increased risk of ADHD symptoms and diagnosis of ADHD among Canadian youth, particularly among adolescents. Prospective studies are needed to confirm these results.

Research paper thumbnail of Youths’ Perspectives on Their Relational Identity Development through Residential Treatment

Journal of Therapeutic Schools and Programs

Research paper thumbnail of Fluoride exposure and thyroid function among adults living in Canada: Effect modification by iodine status

Environment International

Research paper thumbnail of Investigating Patterns of Participation and Conversation Content in an Online Mentoring Program for Northern Canadian Youth

Mentoring & Tutoring: Partnership in Learning, 2015

In this study, we describe participant characteristics, conversation content, and program success... more In this study, we describe participant characteristics, conversation content, and program success of an online mentoring program for northern Canadian youth. We investigate the associations between demographics and program success. The profiles and conversations of students and mentors that participated in the program between 2009 and 2013 were analyzed. Students were categorized into two groups (high and low engagement) based on the number of words written to their mentors. The high group contained proportionally more urban than rural students and equal proportions of Aboriginal and non-Aboriginal students, while the low group contained equal numbers of rural and urban students and proportionally more Aboriginal than non-Aboriginal students. This study provides valuable information on the use of online mentoring in northern communities.

Research paper thumbnail of Inside the adolescent brain: a commentary on the Special Issue

Brain and cognition, 2014

Research paper thumbnail of Laying the Groundwork: A Practical Guide for Ethical Research with Indigenous Communities

International Indigenous Policy Journal, Mar 10, 2017

Although there are numerous ethical guidelines for research with Indigenous communities, not all ... more Although there are numerous ethical guidelines for research with Indigenous communities, not all research is conducted in an ethical, culturally respectful, and effective way. To address this gap, we review four ethical frameworks for research with Indigenous Peoples in Canada. Drawing upon our experiences conducting a transformative social justice research project in five Indigenous communities, we discuss the ethical tensions we have encountered and how we have attempted to address these challenges. Finally, drawing on these experiences, we make recommendations to support those planning to conduct research with Indigenous Peoples in Canada. We discuss the importance of training to highlight the intricacies and nuances of bringing the ethical guidelines to life through co-created research with Indigenous communities.

Research paper thumbnail of Urinary Fluoride Levels Among Canadians and the Association Between Fluoride Exposure and Attention Deficit Hyperactivity Disorder

Fluoride has been identified as a developmental neurotoxin-a claim that is uncontested at high ex... more Fluoride has been identified as a developmental neurotoxin-a claim that is uncontested at high exposure levels, but remains debated at low exposure levels. In Canada, 39% of municipalities add fluoride to their drinking water at a recommended level of 0.7ppm. Exposure to fluoride has been linked with increased prevalence of attention deficit hyperactivity disorder (ADHD) in the United States and symptoms of inattention in Mexican children. This dissertation consists of one study examining the association between fluoride exposure and symptoms of ADHD in youth, and a second study examining the predictors of an individual's level of urinary fluoride. Study 1 used cross-sectional data on youth 6 to 17 years of age from the Canadian Health Measures Survey (CHMS, Cycles 2 and 3). Urinary fluoride concentrations were measured in spot samples and adjusted for specific gravity (UF SG , n=1877) and water fluoride concentrations were measured in tap water samples (n=980). We used logistic regression to test the association between fluoride exposure and ADHD diagnosis and linear regression to examine the relationship between fluoride exposure and the hyperactive-inattention subscale score on the Strengths and Difficulties Questionnaire (SDQ). UF SG did not predict ADHD diagnosis or SDQ score, whereas a 1 mg/L increase in tap water fluoride level was associated with 6.1 times higher odds of an ADHD diagnosis (95% CI = 1.60, 22.8) and a 1.5 increase in SDQ score for adolescents. Study 2 used data from Cycle 3 of the CHMS to examine factors that influence urinary fluoride levels in a sample of 1629 individuals aged 3 to 79 years. In the linear regression models, tap water fluoride level, community water fluoridation status, age, sex, BMI, smoking allowed in the home, and tea consumption were significant predictors of UF SG. Community water fluoridation and tap water fluoride were associated with higher levels of fluoride excretion and with an increased risk of ADHD symptoms and diagnosis among Canadian youth. These findings highlight the need to identify subgroups who may have especially high levels of exposure and to further investigate the potential for fluoride-mediated developmental neurotoxicity in populations with community water fluoridation.

Research paper thumbnail of Corrigendum to Association of water fluoride and urinary fluoride concentrations with attention deficit hyperactivity disorder in Canadian youth

Environment International

Research paper thumbnail of Cyberbullying in Canada

International Perspectives on Cyberbullying, 2018

Cyberbullying is a significant problem in Canada, with high prevalence rates that have remained s... more Cyberbullying is a significant problem in Canada, with high prevalence rates that have remained stable over the past decade (Boak et al. 2016; Craig et al. 2016). A number of highly publicized Canadian cases have underscored the significant implications of involvement in cyberbullying. For example, Amanda Todd, a 15-year-old from western Canada, was lured by a man who manipulated her to share intimate pictures of herself with him (BBC News 2014). When these pictures were posted to Facebook, Amanda was severely bullied by peers at school, causing her to change schools a number of times. She posted a video on YouTube that detailed her struggles with cyberbullying before taking her own life (BBC News 2014). Another young woman, Rehtaeh Parsons, had a photo of her sexual assault shared with peers via text messages (Gillis 2013). After

Research paper thumbnail of The Development of Self in Relationships: Youths' Narratives of Change Through a Residential, Wilderness and Family Therapy Intervention

Research paper thumbnail of Fluoride Exposure and Thyroid Function among Iodine Deficient Adults in Canada

ISEE Conference Abstracts, 2018

Background: Fluoride exposure has the potential to disrupt thyroid functioning, though adequate i... more Background: Fluoride exposure has the potential to disrupt thyroid functioning, though adequate iodine intake may mitigate this effect. This study is the first population-based study to examine the...

Research paper thumbnail of Urinary Fluoride Levels among Canadians with and without Community Water Fluoridation

International Journal of Environmental Research and Public Health, 2021

Drinking water is a major source of dietary fluoride intake in communities with water fluoridatio... more Drinking water is a major source of dietary fluoride intake in communities with water fluoridation. We examined the association between urinary fluoride adjusted for specific gravity (UFSG) and tap water fluoride levels, by age and sex, among individuals living in Canada. Participants included 1629 individuals aged 3 to 79 years from Cycle 3 (2012–2013) of the Canadian Health Measures Survey. We used multiple linear regression to estimate unique associations of tap water fluoride levels, age, sex, ethnicity, body mass index (BMI), use of fluoride-containing dental products, smoking in the home, and tea consumption with UFSG. UFSG concentration was significantly higher among participants who received fluoridated drinking water (mean = 1.06 mg/L, standard deviation = 0.83) than among those who did not (M = 0.58 mg/L, SD = 0.47), p < 0.01. UFSG increased over adulthood (ages 19 to 79). Higher UFSG concentration was associated with being female, tea drinking, and smoking in the home....

Research paper thumbnail of Better Relationships, Mental Wellness, and Self-Development: What Parents Expect from Residential Treatment for Their Struggling Youth

Journal of Therapeutic Schools and Programs

Parents often initiate treatment for their youth with substance use or mental health issues. For ... more Parents often initiate treatment for their youth with substance use or mental health issues. For this reason, parental expectations of treatment are helpful in considering the nature of parental engagement in the treatment process and possible barriers to treatment. The goal of this study was to better understand the expectations of parents who sought residential treatment for their youth. From 638 potential parent applications, 28 individual applications were randomly selected for in-depth qualitative analysis. The most frequently expressed expectation was for youth to have better relationships with their family and with peers. Implications for treatment program design, effectiveness, and evaluation are discussed.

Research paper thumbnail of Association of water fluoride and urinary fluoride concentrations with attention deficit hyperactivity disorder in Canadian youth

Environment International

Background: Exposure to fluoride has been linked with increased prevalence of attention deficit h... more Background: Exposure to fluoride has been linked with increased prevalence of attention deficit hyperactivity disorder (ADHD) in the United States and symptoms of inattention in Mexican children. We examined the association between fluoride exposure and attention outcomes among youth living in Canada. Method: We used cross-sectional data collected from youth 6 to 17 years of age from the Canadian Health Measures Survey (Cycles 2 and 3). Urinary fluoride concentration adjusted for specific gravity (UFSG) was available for 1877 participants. Water fluoride concentration measured in tap water samples was available for 980 participants. Community water fluoridation (CWF) status was determined by viewing reports on each city&#39;s website or contacting the water treatment plant. We used logistic regression to test the association between the three measures of fluoride exposure and ADHD diagnosis. Linear regression was used to examine the relationship between the three measures of fluoride exposure and the hyperactivity/inattention score on the Strengths and Difficulties Questionnaire (SDQ). Results: UF SG did not significantly predict ADHD diagnosis or hyperactive/inattentive symptoms. A 1 mg/L increase in tap water fluoride level was associated with a 6.1 times higher odds of an ADHD diagnosis (95% CI = 1.60, 22.8). A significant interaction between age and tap water fluoride level (p = .03) indicated a stronger association between tap water fluoride and hyperactivity/inattention symptoms among older youth. A 1 mg/L increase in water fluoride level was associated with a 1.5 SDQ score increase (95% CI: 0.23, 2.68, p = .02) for youth at the 75th percentile of age (14 years old). Similarly, there was a significant interaction between age and CWF. At the 75th percentile of age (14 years old), those living in a fluoridated region had a 0.7-point higher SDQ score (95% CI = 0.34, 1.06, p &lt; .01) and the predicted odds of an ADHD diagnosis was 2.8 times greater compared with youth in a non-fluoridated region (aOR = 2.84, 95% CI: 1.40, 5.76, p &lt; .01). Discussion: Exposure to higher levels of fluoride in tap water is associated with an increased risk of ADHD symptoms and diagnosis of ADHD among Canadian youth, particularly among adolescents. Prospective studies are needed to confirm these results.

Research paper thumbnail of Youths’ Perspectives on Their Relational Identity Development through Residential Treatment

Journal of Therapeutic Schools and Programs

Research paper thumbnail of Fluoride exposure and thyroid function among adults living in Canada: Effect modification by iodine status

Environment International

Research paper thumbnail of Investigating Patterns of Participation and Conversation Content in an Online Mentoring Program for Northern Canadian Youth

Mentoring & Tutoring: Partnership in Learning, 2015

In this study, we describe participant characteristics, conversation content, and program success... more In this study, we describe participant characteristics, conversation content, and program success of an online mentoring program for northern Canadian youth. We investigate the associations between demographics and program success. The profiles and conversations of students and mentors that participated in the program between 2009 and 2013 were analyzed. Students were categorized into two groups (high and low engagement) based on the number of words written to their mentors. The high group contained proportionally more urban than rural students and equal proportions of Aboriginal and non-Aboriginal students, while the low group contained equal numbers of rural and urban students and proportionally more Aboriginal than non-Aboriginal students. This study provides valuable information on the use of online mentoring in northern communities.

Research paper thumbnail of Inside the adolescent brain: a commentary on the Special Issue

Brain and cognition, 2014

Research paper thumbnail of Laying the Groundwork: A Practical Guide for Ethical Research with Indigenous Communities

International Indigenous Policy Journal, Mar 10, 2017

Although there are numerous ethical guidelines for research with Indigenous communities, not all ... more Although there are numerous ethical guidelines for research with Indigenous communities, not all research is conducted in an ethical, culturally respectful, and effective way. To address this gap, we review four ethical frameworks for research with Indigenous Peoples in Canada. Drawing upon our experiences conducting a transformative social justice research project in five Indigenous communities, we discuss the ethical tensions we have encountered and how we have attempted to address these challenges. Finally, drawing on these experiences, we make recommendations to support those planning to conduct research with Indigenous Peoples in Canada. We discuss the importance of training to highlight the intricacies and nuances of bringing the ethical guidelines to life through co-created research with Indigenous communities.