shorter menstrual cycles associated with chlorination by products in drinking water l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Shorter Menstrual Cycles Associated with Chlorination By-Products in Drinking Water PowerPoint Presentation
Download Presentation
Shorter Menstrual Cycles Associated with Chlorination By-Products in Drinking Water

Loading in 2 Seconds...

play fullscreen
1 / 13

Shorter Menstrual Cycles Associated with Chlorination By-Products in Drinking Water - PowerPoint PPT Presentation


  • 104 Views
  • Uploaded on

Shorter Menstrual Cycles Associated with Chlorination By-Products in Drinking Water. Gayle Windham, K Waller, M Anderson, L Fenster, P Mendola, S Swan California Department of Health Services Environmental Health Investigations Branch (Work supported in large part by USEPA).

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Shorter Menstrual Cycles Associated with Chlorination By-Products in Drinking Water' - brilliant


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
shorter menstrual cycles associated with chlorination by products in drinking water

Shorter Menstrual Cycles Associated with Chlorination By-Products in Drinking Water

Gayle Windham, K Waller, M Anderson,

L Fenster, P Mendola, S Swan

California Department of Health ServicesEnvironmental Health Investigations Branch

(Work supported in large part by USEPA)

tthm levels and menstrual cycling
TTHM Levels and Menstrual Cycling

Background

  • Found association of SAB and high consumption of water with high TTHM and BDCM levels.
  • Other studies confirm increased risk of adverse pregnancy outcomes with chlorination by-products.

Purpose

  • THMs associated with other reproductive endpoints?
  • Identify possible mechanisms for the SAB effects.
  • Examine THM exposure and menstrual cycle function in a study of 400 premenopausal women.
women s reproductive health study methods
Women’s Reproductive Health Study Methods
  • Prospective Study of Kaiser members in Santa Clara County
  • Women “at risk” of pregnancy, married, ages 18-39
  • Urine collected daily (about 6 months) to measure:
    • Steroid metabolites (E1C, PdG) — menstrual cycle function
    • hCG — early pregnancy loss
  • Data collected 1990-91 (follow-up 2 years later)
data collection instruments
Data Collection Instruments
  • Screening Interview — phone
    • eligibility criteria
  • Baseline Questionnaire — phone
    • # glasses unheated tap water at home
    • # glasses hot tap at home
    • # glasses bottled water/day (and brand)
    • # showers at home (and length)/week
    • Demographics and covariates
  • Daily Diary — self-administered
assignment of thm level
Assignment of THM Level
  • Geocode residence address to identify water utility company
  • Obtain utility THM monitoring data (total and individual)
  • Cycle-specific THM levels estimated:
    • 90-day window, starting 60 days before cycle start
    • average all utility monitoring points
    • weighted if moved
    • average two closest to window, if none during
  • Woman-level TTHM from average of cycle-specific levels
results subject characteristics n 401
Results — Subject Characteristics (N=401)

% TTHMCharacteristic N % >80 µg/L

Age 21-29 years 137 34.2 2

30-34 years 159 39.6 3

35-39 years 105 26.2 4

Race White 283 70.6 3

Hispanic 52 13.0 4

Other 66 16.4 3

Education No College 89 22.2 3

Some College 151 37.7 2

College Graduate 161 40.2 4

Pregnancies 0 48 12.0 4

≥1, no losses 256 63.8 2

≥1, ≥1 loss 97 24.2 4

menstrual cycle length parameters by total trihalomethane level
Menstrual Cycle Length Parameters byTotal Trihalomethane Level

TTHM Level (µg/L) 0-40 >40-60 >60

Cycle Length

Mean (s.e.) 29.7 (0.26) 29.3 (0.28) 28.7 (0.28)

Adj. Difference (CI) Ref -0.50 (-1.1, 0.11) -1.1 (-1.8, -0.40)

Follicular Phase

Mean (s.e.) 16.9 (0.27) 16.5 (0.29) 16.0 (0.30)

Adj. Difference (CI) Ref -0.39 (-0.98, 0.20) -0.94 (-1.6, -0.24)

Luteal Phase

Mean (s.e.) 12.9 (0.09) 12.8 (0.11) 13.0 (0.10)

Adj. Difference (CI) Ref -0.08 (-0.33, 0.18) 0.07 (-0.20, 0.35)

length parameters by total trihalomethane daily consumption level

Length Parameters by Total Trihalomethane Daily Consumption Level

TTHM Consumption Level (µg/day) 0 >0-40 >40

Cycle Length

N 449 717 458

Mean (s.e.) 29.8 (0.39) 29.43 (0.28) 28.5 (0.33)

Adj. Difference (CI) Ref -0.23 (-1.2, 0.77) -1.1 (-2.2, -0.06)

Follicular Phase

N 402 676 436

Mean (s.e.) 17.1 (0.43) 16.6 (0.30) 15.8 (0.34)

Adj. Difference (CI) Ref -0.32 (-1.4, 0.77) -1.1 (-2.2, 0.03)

length parameters by quartiles of chloroform and brominated trihalomethane levels

Length Parameters by Quartiles of Chloroform and Brominated Trihalomethane Levels

Quartile of Exposure

1 2-3 4

Mean in Days Difference Difference

(s.e.) (95% CI) (95% CI)

Cycle Length

Chloroform 29.6 (0.30) -0.43 (-0.99, 0.13) -0.30 (-1.0, 0.40)

Sum of Brominated 30.0 (0.34) -0.72 (-1.4, -0.04) -1.2 (-2.0, -0.40)

Follicular Phase

Chloroform 16.8 (0.31) -0.42 (-0.96, 0.12) -0.13 (-0.82, 0.56)

Sum of Brominated 17.2 (0.35) -0.66 (-1.3, 0.02) -1.1 (-1.9, -0.29)

tthm levels and menstrual cycling12
TTHM Levels and Menstrual Cycling

Strengths

  • Prospective study
  • TTHM exposure from existing records in narrow time frame
  • Information on some water use patterns
  • Endpoint determined from biologic measures (vs. self-report)
  • Adjusted for several potential confounders
  • First study of reproductive function in non-pregnant women

Limitations

  • Potential exposure misclassification (utility average)
  • No information on exposure outside the home
  • Study sample may not represent full range of cycle variability
conclusions and summary
Conclusions and Summary
  • Increasing TTHM level is associated with decreasing cycle length, primarily in the follicular phase
  • This decrease is associated with the brominated THMs, primarily chlorodibromomethane
  • Combining consumption and TTHM level reveals similar, but not greater, associations
  • Accounting for showering also does not reveal stronger associations

Confirm effects on ovarian function in other studies