The potential for human exposure to pesticides exists particularly for agricultural workers (i.e. migrant workers) and individuals within close proximity to pesticide-sprayed crops (i.e. those living on or near agricultural farms). Children, through biology and behavior, may be more susceptible and vulnerable to exposure to pesticides than adults. The purpose of this study was to examine young populations particularly at-risk for occupational or accidental exposure to pesticides and determine associated behavioral, emotional, and physical symptoms. A total of 444 students from two South Texas school districts completed questionnaires assessing level of risk of exposure to pesticides and were categorized into at-risk and low risk categories. Physical, emotional, and behavioral symptoms were obtained using the Youth Self-Report. Children who were at-risk demonstrated significantly higher scores on the Youth Self-Report (YSR) in the areas of anxious/depressed, attention problems, social problems, somatic complaints, thought problems, withdrawal, internalizing behaviors, and total problem behaviors than children who were at lower risk of pesticide exposure. Odds ratios were obtained and suggested that children in the at-risk category were more five times more likely to score in the clinically significant range on the Attention Problems subscale, and three times more likely to score in the clinically significant range on the Internalizing behavior composite. These findings suggest that children who may be at higher risk for pesticide exposure may also be at higher risk for physical, behavioral, and emotional problems compared to children who are at lower risk. This information is intended to benefit schools and health care professionals who work with rural or migrant populations involved in the agricultural trade. Future research will be needed to assess through biomarkers the degree of measurable pesticide exposure in comparison to parent reports, teacher reports, school achievement, neuropsychological testing, and medical records.

by Edwina Po Sau Man. / The "0" & "1" in the title are subscripts. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 81-86). / Abstract --- p.II / Acknowledgment --- p.IV / Abbreviations --- p.V / List of Tables --- p.VIII / List of Figures --- p.IX / Table of Contents --- p.XII / Chapter Section 1 --- Introduction --- p.1 / Chapter 1.1 --- Photosynthesis --- p.1 / Chapter 1.2 --- Site of Photosynthesis --- p.3 / Chapter 1.3 --- The Structure of ATPase --- p.6 / Chapter 1.3.1 --- Functions of the Subunits of CF1 --- p.9 / Chapter 1.3.1.1 --- The ε - Subunit --- p.9 / Chapter 1.3.1.2 --- The δ - Subunit --- p.9 / Chapter 1.3.1.3 --- The γ- Subunit --- p.10 / Chapter 1.3.1.4 --- The α- and β- Subunits --- p.10 / Chapter 1.4 --- "Photosynthetic Electron Transport, Δ pH and Phosphorylation inside Chloroplasts" --- p.12 / Chapter 1.5 --- Pesticides --- p.16 / Chapter 1.5.1 --- Paraquat --- p.17 / Chapter 1.5.2 --- Carbamates --- p.20 / Chapter 1.6 --- Objectives of the Study --- p.21 / Chapter Section 2 --- Materials and Methods --- p.22 / Chapter 2.1 --- Apparatus --- p.22 / Chapter 2.2 --- Materials --- p.24 / Chapter 2.2.1 --- Reagents and Buffers for assay of Proton Transport --- p.25 / Chapter 2.2.2 --- Pesticides --- p.26 / Chapter 2.2.3 --- Buffers for SDS-PAGE --- p.27 / Chapter 2.2.4 --- Reagents of Bradford Protein Assay --- p.31 / Chapter 2.3 --- Methods --- p.32 / Chapter 2.3.1 --- Determination of ChlorophyllContent --- p.32 / Chapter 2.3.2 --- Determination of Protein Content in Chloroplast Thylakoids --- p.33 / Chapter 2.3.3 --- Measurement of Proton Transport --- p.34 / Chapter 2.3.3.1 --- Pesticide Concentration Study --- p.36 / Chapter 2.3.3.2 --- Time Course Study --- p.36 / Chapter 2.3.3.3 --- Kinetic Analysis of the Effects of Pesticides on Chloroplast Thylakoids Before and After Illumination --- p.37 / Chapter 2.3.3.4 --- Study of the Combined Effects of Two Pesticides --- p.37 / Chapter 2.3.4 --- Effect of Pesticides on Chloroplast Membranes by SDS-PAGE --- p.38 / Chapter Section 3 --- Results --- p.39 / Chapter 3.1 --- Pesticide Concentration Study --- p.39 / Chapter 3.1.1 --- Paraquat Dichloride --- p.39 / Chapter 3.1.2 --- Methyl Carbamate --- p.41 / Chapter 3.1.3 --- Ethyl Carbamate --- p.43 / Chapter 3.1.4 --- Pyridinol Carbamate --- p.45 / Chapter 3.1.5 --- Pyrrolidinedithiocarbamate --- p.47 / Chapter 3.1.6 --- Diethyldithiocarbamic Acid --- p.49 / Chapter 3.1.7 --- Summary of the Pesticides Concentration Study --- p.51 / Chapter 3.2 --- Time-course Study --- p.52 / Chapter 3.3 --- Kinetic Analysis of the Effects of Pesticides on Chloroplast Thylakoids Before and After Illumination --- p.53 / Chapter 3.3.1 --- Paraquat Dichloride --- p.53 / Chapter 3.3.2 --- Methyl Carbamate --- p.56 / Chapter 3.3.3 --- Ethyl Carbamate --- p.57 / Chapter 3.3.4 --- Pyridinol Carbamate --- p.58 / Chapter 3.3.5 --- Pyrrolidinedithiocarbamate --- p.59 / Chapter 3.3.6 --- Diethyldithiocarbamic Acid --- p.60 / Chapter 3.4 --- Combined Effects of Paraquat and Carbamates --- p.61 / Chapter 3.4.1 --- Paraquat and Methyl Carbamate --- p.61 / Chapter 3.4.2 --- Paraquat and Ethyl Carbamate --- p.64 / Chapter 3.4.3 --- Paraquat and Pyridinol Carbamate --- p.66 / Chapter 3.4.4 --- Paraquat and Pyrrolidinedithiocarbamate --- p.69 / Chapter 3.4.5 --- Paraquat and Diethyldithiocarbamic Acid --- p.71 / Chapter 3.5 --- Gel Electrophoresis --- p.73 / Chapter Section 4 --- Discussion --- p.75 / Chapter Section 5 --- Conclusion --- p.80 / Chapter Section 6 --- References --- p.81 / References --- p.81 / Appendix I Kinetic Analysis of Pesticides with Chloroplast Thylakoids upon Illumination --- p.87 / Appendix II Kinetic Analysis of Pesticides with Chloroplast Thylakoids in the Dark --- p.88 / Appendix III The Initial Rate of Proton Transport in Chloroplast Thylakoids with Different Pesticides --- p.89 / Appendix IV The Conversion of Equivalent Protons from pH Changes --- p.90 / Appendix V Calculation of Proton Transport (%) --- p.91 / Appendix VI Determination of Protein Content in Chloroplast Thylakoids --- p.92 / Appendix VII Calculaiton of Relative Mobility (Rf) --- p.93

Graduation date: 1994

Cette thèse porte sur l’étude des composés organiques semi-volatils, notamment les pesticides et les composés nitro-aromatiques dans les deux compartiments l’eau et l’atmosphère. La première partie de ce travail concerne l'optimisation des différents paramètres expérimentaux (concentration initiale des composés, concentration de l’électrolyte support, température et la densité de courant imposé) de la dégradation de la cypermethrine et du 2-Nitrobenzaldehyde (2-NBA) par oxydation direct moyennant les électrodes de l'oxyde d'étain (SnO2) et le diamant dopé au bore (DDB). Cette dégradation a été suivie par les analyses de la demande chimique en oxygène (DCO) et la chromatographie en phase gazeuse. Les résultats obtenus montrent que le taux de minéralisation dépasse 80 % pour le cypermethrine en utilisant le DDB. La deuxième partie est consacrée à l'étude de la réactivité du bupirimate vis-à-vis de l’ozone et les radicaux OH• en phase hétérogène. Les résultats obtenus montrent que les valeurs de la constante cinétique pour la réaction du bupirimate avec les radicaux OH• et l’ozone sont respectivement de l’ordre de 1,06 x 10-12 et 5,4 x 10-20 (cm3 molecule-1 s-1). La durée de vie du bupirimate est de plusieurs mois par rapport à l'ozone et de quelques jours par rapport aux radicaux OH•. Les spectres UV et la réactivité homogène vis-à-vis des radicaux OH• du 2-Nitrobenzaldehyde (2-NBA) a été déterminé en phase gazeuse. Les études cinétiques ont été réalisées dans une chambre atmosphérique couplée à un spectromètre IR. Les résultats obtenus montrent que le 2-NBA est sensibles à la photolyse dans l’atmosphère et que sa réactivité vis-à-vis des radicaux OH• est non négligeable. En effet, la durée de vie atmosphérique de ce composé est relativement courte. Elle varie de quelques minutes à quelques heures. Le 2-NBA est donc non persistant dans l’atmosphère. / This thesis focused on the study of semi-volatile organic compounds (SVOC), including pesticides and nitro-aromatics compounds in the two compartments, water and atmosphere. The first part of this work concerns the optimization of the different experimental parameters in order to mineralize two compounds (cypermethrin and of 2-Nitrobenzaldehyd), those parameters are initial concentration of compounds, concentration of the electrolyte support, temperature and the density of the current imposed. This mineralization has been done by a direct oxidation through the electrodes of the tin oxide (SnO2) and Boron Doped Diamond (BDD). The degradation process has been followed by the DCO analyzes and the gas chromatography. It has been shown that the rate of mineralization exceeds 80 % for the cypermethrine compound using BDD electrode. The second part is devoted to study the reactivity of bupirimate in heterogeneous phase using ozone and OH radicals as oxidant. The obtained results show that the rate constant values of the analyte are (1,06 ± 0,87) x 10-12 and (5,4 ± 0,3) x 10-20 (cm3 molecule-1 s-1) relative to heterogeneous OH-oxidation and O3, respectively. Such values implicate tropospheric life-times that vary from a few days to several months, meaning that these compounds are relatively persistent and may be transported to regions far from their point of application. The UV-absorption spectra and homogeneous OH-reactivity of 2-Nitrobenzaldehyde compound in the gas phase are investigated. The kinetic studies have been carried out in an atmospheric chamber coupled to an IR spectrometer. The results obtained indicate that the compound studied is susceptible to photolysis in the atmosphere and he exhibit strong reactivity towards OH-radicals. Generally speaking, the atmospheric life-time of this compound is relatively short, in the order of a few minutes to hours and he is non-persistent. Rate constants present a slight variation with the temperature.

O uso intensivo de agrotÃxicos e fertilizantes ocasiona danos ambientais e intoxicaÃÃo humana. Em humanos, essa intoxicaÃÃo se manifesta por vÃrios sinais e sintomas. No municÃpio de Limoeiro do Norte-CE, os trabalhadores do agronegÃcio do abacaxi queixam-se de problemas de saÃde devido à exposiÃÃo aos agroquÃmicos em suas atividades laborais. O objetivo deste estudo à caracterizar os agravos à saÃde humana entre os trabalhadores do agronegÃcio do abacaxi expostos ao uso de agrotÃxico-fertilizantes quÃmicos no municÃpio de Limoeiro do Norte, localizado no Vale do Jaguaribe-CE. Trata-se de um estudo transversal, descritivo, com amostragem intencional, composta de 75 pessoas mobilizadas por redes sociais, utilizando abordagem metodolÃgica quantitativa e qualitativa. Realizou-se a aplicaÃÃo de um formulÃrio estruturado, contendo dados socioeconÃmicos, hÃbitos de vida, histÃria pregressa familiar, caracterizaÃÃo do trabalho, exposiÃÃo do trabalhador, orientaÃÃes para o trabalhador em Ãrea de uso de agrotÃxicos e medidas de controle do risco adotadas pela empresa, relaÃÃes de trabalho, caracterizaÃÃo clÃnico-toxicolÃgica, histÃria clÃnica e exame fÃsico. O processamento dos dados ocorreu no Ele info 6, versÃo 6.04 d, e a anÃlise, no Stata, versÃo 9, considerando intervalo de confianÃa de 95% e valor de P < 0,05. Pela complexidade do objeto em estudo, realizou-se abordagem qualitativa, efetivando-se uma visita a uma empresa do agronegÃcio e dois grupos focais. Para interpretaÃÃo dos sentidos atribuÃdos pelos informantes ao fenÃmeno investigado, foi realizada uma leitura aprofundada das falas nos grupos focais. A amostra à caracterizada por adultos jovens, do sexo masculino, com faixa etÃria entre 19 e 43 anos, renda familiar de 1 a 2 salÃrios mÃnimos em 80,3%. Houve negatividade de 88,0% e de 44,0% para o uso de tabaco e bebida alcoÃlica respectivamente. Cerca de 50,6% dos trabalhadores rurais entrevistados tinham mais de 13 anos de atividade laboral na agricultura e, destes, 82,6% eram assalariados, tendo de 1 a 4 anos na empresa. Entre os entrevistados, 94,6% afirmaram contato com os agrotÃxicos/fertilizantes, sendo que 56,6% consideraram ser indireto. A quase totalidade (98,6%) considerou que o contato poderia causar mal à saÃde, 68,0% nÃo souberam dizer a qual agrotÃxico foram expostos, e 48,0% a qual fertilizante. Dos trabalhadores, 64,0% afirmaram ter algum problema de saÃde, sendo que 34,7% referem de 1-4 sintomas e 18,7% entre 5 e 8 sintomas. Os problemas de saÃde relacionados a sintomas gerais foram 67,0%: 63,0% neurolÃgicos e 59,0% oculares. A cefaleia foi referida por 31,0%, e o ardor ocular, por 45,0%. Os exames de colinesterase plasmÃtica apresentaram-se todos normais; as alteraÃÃes das provas de funÃÃes hepÃticas foram de 53,0%; 13,0% de TGO, 23,5% da TGP e 14,7% de Gama GT. Para a Gama GT, foram observados valores de 107 U/L a 329 U/L em dois trabalhadores. Os valores da FA acima do normal foram em 19,0% dos exames analisados. Entre as bilirrubinas, destacou-se a BD, com 13,0% acima dos valores considerados normais. Clinicamente, foram encontradas doenÃas da pele em 28,0% da amostragem; queixas respiratÃrias em 11,0%; queixas osteomusculares em 18,0% e hipertensÃo de grau leve em 6,7%. As queixas clÃnicas associadas aos sinais e sintomas referidos e alteraÃÃes de alguns exames laboratoriais dos entrevistados sÃo de intoxicaÃÃo crÃnicas e/ou agudas. Portanto a exposiÃÃo a agrotÃxico e a fertilizantes pode causar agravos à saÃde dos trabalhadores do agronegÃcio do abacaxi em Limoeiro do Norte-CE. Estudos prospectivos visando a mensurar o impacto dos agroquÃmicos na vida dos trabalhadores e no sistema de saÃde se fazem necessÃrios. / The intensive use of pesticides and fertilizers cause environmental damage and human poisoning. In humans they can cause poisoning which is manifested by several signs and symptoms. In the town of Limoeiro do Norte-CE/BRAZIL, workers in the pineapple agribusiness area, complain about health problems due to exposure to pesticides in their activities. The objective is to characterize the human health problems among workers exposed to pineapple agribusiness uses of pesticides, chemical fertilizers, in the town of Limoeiro do Norte-CE/BRAZIL, located in the valley of Jaguaribe-CE/BRAZIL. This is a descriptive study, with purposive samples, consisting of 75 people mobilized by social networks, using the quantitative and qualitative methodology. We carried out the implementation of a structured form containing data on socioeconomic, lifestyle, family medical history, characteristics of work, worker exposure, guidelines for field workers in pesticide use area and risk control measures adopted by the company, work relationship, clinical and toxicological characteristics, medical history and physical examination. The data processing occurred in Ele info 6, version 6.04 d, and the analysis in Stata version 9. Considering confidence interval of 95% and P value <0.05. Due to the complexity of the object under study, there was a qualitative approach, resulting to a visit to an agribusiness company and two focus groups. For interpretation about the significance attributed by informants to the investigated phenomenon, we performed a thorough reading of the speeches of focus groups. The sample is characterized by young adults, male, aged between 19 to 43 years. With family incomes from 01 to 02 minimum wages by 80.3%. There was negativity of 88.0% and 44.0% for tobacco use and alcohol consumption. About 50.6% of workers surveyed said they had more than 13 years of labor activity in agriculture, and from these 82.6% were employed, with one to four years in the company. Among the respondents, 94.6% reported contact with pesticides/fertilizers, and 56.6% considered to be indirect. Almost all (98.6%) thought that contact would cause harm to health and that 68.0% could not say to which pesticides they had been exposed to and 48.0% were exposed to fertilizers. 64.0% of workers reported having some health problem, while 34.7% reported symptoms of 1-4 and 18.7% of 5-8 symptoms. Health problems related to general symptoms were 67.0%, neurological 63.0% and 59.0% eyes problems. Headache was reported by 31.0% and 45.0% for ocular burning. The tests showing plasma cholinesterase were all normal, changes in liver function tests were 53.0%, 13.0% of SGOT, SGPT of 23.5% and 14.7% of the Gamma GT. For Gamma GT, values were observed from 107 U/L to 329 U/L in two workers. The values of the FA above normal were in 19.0% of the analyzed exams. Among the bilirubins, the BD was stood out with 13.0% above the normal range. Clinically, skin disease was found in 28.0% of samples; respiratory complaints in 11.0%, 18.0% of musculoskeletal complaints and mild hypertension in 6.7%. The clinical complaints associated with signs and symptoms reported and changes in some laboratory tests by the interviewees are the chronic or acute intoxication. Therefore, exposure to pesticides and fertilizers can be detrimental to the health of workers in the pineapple agribusiness in Limoeiro do Norte-CE/BRAZIL. Prospective studies aimed at measuring the impact of pesticides on workers and on the health system are needed.

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