Male:Female Birth Ratios and Phthalate Levels
Condition: Endocrine Diseases
MeSH terms: Endocrine System Diseases
Study type: Observational

Summary: 
      Objective 1: To assess environmental exposure to chemicals/toxins, including phthalates,
      among rural and urban Mexican American men and women (n=300), aged 18 to 40, in urban
      Baytown, TX and rural Rio Grande Valley (Hidalgo County) communities along the Texas-Mexico
      border region via survey.

      Objective 2: To determine generational sex ratio trends in urban Baytown, TX and along the
      rural Rio Grande Valley (Hidalgo County) utilizing vital statistics data from the Texas
      Department of Health and the Center for Health Statistics.

      Objective 3: To measure urinary phthalate levels and self-reported phthalate exposure in
      Mexican American men and women from urban Baytown, Texas and rural communities along the
      lower Rio Grande Valley (Hidalgo County) on theTexas-Mexico border. To conduct an optional
      procedure, chromosomal sex determination, among a subgroup of 50 persons (13 men + 12 women
      in each community) from participants who complete the survey in Objective 1.
    

Detailed description: 
      Questionnaire:

      If you agree to take part in this study, you will complete a questionnaire about your
      family's characteristics. For example, the questionnaire will have questions about your
      educational level, your eating habits, your health conditions, your family's income level,
      and how many people live in your house. The study doctor will also ask you questions about
      any drugs you may be taking. The questionnaire should take about 30-35 minutes to complete.

      The completed paper questionnaire will be placed in a secured, locked cabinet and will be
      given a code number. Only the researcher in charge of the study will have access to the code
      numbers and be able to link the questionnaire to you. After the study ends and after
      information from the questionnaire has been entered in a password protected database, the
      paper copy of the questionnaire will be sent to M. D. Anderson to be stored for up to 5
      years. After 5 years, it will be destroyed.

      Urine Sample:

      You will have a urine sample collected. Researchers will study the urine samples to learn
      what your level of exposure may be to certain chemicals in the environment, specifically
      chemicals called phthalates. Phthalate is the only chemical that will be measured.

      Additional Information:

      All information collected during this study will be kept strictly confidential, and will not
      contain any personal identifiable information such as your name, address, and/or telephone
      number. All the information will be will be given a code number. To protect confidentiality,
      DNA data will not be linked to participant identifiers. Only the researcher in charge of the
      study will have access to the code numbers and be able to link any information to you. All
      samples and DNA data will be destroyed within three years after the conclusion of the study.

      Length of Study:

      After the questionnaire is complete and the urine sample has been collected, your
      participation on this study will be over.

      This is an investigational study. Up to 300 participants (150 from Baytown,TX and 150 from
      the rural lower Rio Grande Valley in Hidalgo County, TX) will take part in this study. All
      will be enrolled through M. D. Anderson.
    

Intervention name(s): Questionnaire
Intervention type(s): Behavioral
Intervention description(s): Questionnaire about family's characteristics taking about 30-35 minutes to complete.
Other intervention name(s): Survey
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Men and Women of Mexican American origin ages 18 to 40 years, residing in Baytown or the
        lower Rio Grande Valley in Hidalgo County, Texas for at least 45 years.
      
Biospecimen description: 
      Urine sample.
    
Keywords: Endocrine; Environmental Chemicals; Male:Female Birth Ratio; Phthalate Exposure; Generational sex ratio trends; Mexican American; Baytown; Rio Grande Valley; Hidalgo County; Texas