Registration Dossier

Administrative data

Endpoint:
epidemiological data
Type of information:
other: epidemiologic study
Adequacy of study:
supporting study
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: Data are available from a limited number of towns.

Data source

Reference
Reference Type:
publication
Title:
The Effect of Disinfection By-products and Mutagenic Activity on Birth Weight and Gestational Duration
Author:
Wright JM, Schwartz J and Dockery DW
Year:
2004
Bibliographic source:
Environmental Health Perspectives, volume 112, page 920-925

Materials and methods

Endpoint addressed:
toxicity to reproduction / fertility
developmental toxicity / teratogenicity
Principles of method if other than guideline:
In the present study, data from several years of birth certificate data were used to examine the relationship between indices of fetal development and various town averate exposure metrics. Data from 1997-1998 on haloacetic acid (total haloacetic acids, dichloroacetic acid and trichloroacetic acid) were available for limited number of towns.

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Type of population:
general
Details on study design:
The Massachusetts Department of Public Health (Boston, MA) supplied 1995–1998 birth certificate data for towns with populations > 10,000. These data contained detailed maternal and infant information including birth weight and gestational age. We excluded infants with implausible values for birth weight (< 200 g) and gestational age (< 22 or > 45 weeks) and those born to nonresidents. The remaining birth data were linked with drinking water disinfection by-products (DBP) and mutagenicity measurements to examine the effect of maternal third-trimester exposure on mean birth weight and small for gestational age (SGA) infancy in term births and preterm delivery and mean gestational age in all births.
Details on exposure:
Haloacetic acid (HAA) samples were collected by 17 towns on a weekly to quarterly basis from 1997 to 1998 and were analyzed using gas chromatography (U.S. EPA method 552; U.S. EPA 1995). Total HAAs included monochloroacetic, dichloroacetic, trichloroacetic, monobromoacetic, and dibromoacetic acids. Monochloroacetic acid, monobromoacetic acid, and dibromoacetic acid rarely exceeded the detection limit in these sampled communities, so we restricted the data analysis to dichloroacetic acid, trichloroacetic acid, and total HAAs.

Results and discussion

Results:
Birth weight: No associations were detected for high third-trimester haloaceti acids exposures, but birth weight increases > 20 g were observed for intermediate total haloacetic and trichloroacetic acids.
Gestational age: Trichloroacetic acid > 27 μg/L was associated with shorter gestational duration (–0.9 days; 95% CI, –1.7 to –0.1) compared with ≤ 18 μg/L.
Small for gestational age (SGA) infancy: We did not detect an increased risk of SGA infancy for high haloacetic acid exposures, but inverse associations were detected for intermediate trichloroacetic and dichloroacetic acid exposures.
Preterm delivery: an increased risk was observed for high trichloroacetic (OR = 1.33; 95% CI, 0.77 to 2.30) and total HAAs (OR = 1.48; 95% CI, 0.84 to 2.61).

Applicant's summary and conclusion

Conclusions:
Birth weight: No associations were detected for high third-trimester haloaceti acids exposures, but birth weight increases > 20 g were observed for intermediate total haloacetic and trichloroacetic acids.
Gestational age: Trichloroacetic acid > 27 μg/L was associated with shorter gestational duration (–0.9 days; 95% CI, –1.7 to –0.1) compared with ≤ 18 μg/L.
Small for gestational age (SGA) infancy: We did not detect an increased risk of SGA infancy for high haloacetic acid exposures, but inverse associations were detected for intermediate trichloroacetic and dichloroacetic acid exposures.
Preterm delivery: an increased risk was observed for high trichloroacetic (OR = 1.33; 95% CI, 0.77 to 2.30) and total HAAs (OR = 1.48; 95% CI, 0.84 to 2.61).
Executive summary:

In the present study, data from several years of birth certificate data were used to examine the relationship between indices of fetal development and various town averate exposure metrics. Data from 1997-1998 on haloacetic acid (total haloacetic acids, dichloroacetic acid and trichloroacetic acid) were available for limited number of towns.

Birth weight: No associations were detected for high third-trimester haloaceti acids exposures, but birth weight increases > 20 g were observed for intermediate total haloacetic and trichloroacetic acids.

Gestational age: Trichloroacetic acid > 27 μg/L was associated with shorter gestational duration (–0.9 days; 95% CI, –1.7 to –0.1) compared with ≤ 18 μg/L.

Small for gestational age (SGA) infancy: We did not detect an increased risk of SGA infancy for high haloacetic acid exposures, but inverse associations were detected for intermediate trichloroacetic and dichloroacetic acid exposures.

Preterm delivery: an increased risk was observed for high trichloroacetic (OR = 1.33; 95% CI, 0.77 to 2.30) and total HAAs (OR = 1.48; 95% CI, 0.84 to 2.61).