Chloroethylene

Epidemiological data

Administrative data

Endpoint:

epidemiological data

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: In the present record epidemiological data on developmental toxicity are combined. The studies have been published in peer-reviewed literature and are considered to be adequate for assessment.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Carcinogenic, mutagenic, and teratogenic risks associated with vinyl chloride.

Author:

Infante, P.F., Wagoner, J.K. and Waxweiler, R.J.

Year:

1976

Bibliographic source:

Mutat Res 41:131-142

Reference 2

Reference Type:

publication

Title:

Congenital Central Nervous System Malformations and Vinyl Chloride Monomer Exposure: A Community Study.

Author:

Edmonds, L.D., Anderson, C.E., Flynt, J.W. and James, L.M.

Year:

1978

Bibliographic source:

Teratology 17:137-142.

Reference 3

Reference Type:

publication

Title:

Central nervous system malformations in relation to two polyvinyl chloride production facilities.

Author:

Rosenman, K.D., Rizzo, J.E., Conomos, M.G. and Halpin, G.J.

Year:

1989

Bibliographic source:

Archives Env Health 44:279-282.

Reference 4

Reference Type:

publication

Title:

Evaluation of the Association Between Birth Defects and Exposure to Ambient Vinyl Chloride

Author:

Theriault, G.; Iturra, H.; Gingras, S

Year:

1983

Bibliographic source:

Teratology 27, 359 - 370

Materials and methods

Endpoint addressed:

developmental toxicity / teratogenicity

Principles of method if other than guideline:

Epidemiological studies

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Chloroethylene

EC Number:

200-831-0

EC Name:

Chloroethylene

Cas Number:

75-01-4

Molecular formula:

C2H3Cl

IUPAC Name:

chloroethene

Method

Type of population:

general

Results and discussion

Results:

Although a statistically significant increase in congenital abnormalities has been observed in members of some communities near a vinyl chloride processing facility, reports have failed to establish a statistically significant association between developmental toxicity and either parental occupation or proximity to the facility.

Any other information on results incl. tables

Method

Analysis of numbers of congenital malformations in three communities in the northeast part of during 1970 - 1973. The three communities have PVC production plants.

Results

The rate of malformations per 1,000 births for the three communities studied was significantly higher than that in control areas (Table 1).  The greatest excess included malformations of the CNS, cleft lip and palate, club foot and genital organs (Table 2).

                         Table 1
          Malformation rates per 1000 live births in 3 selected communities

                                    Malformations
                                       number       number
Area           Births     Rate/1000   observed     expected
Entire state  719,287         10.1       7295            --
 of Ohio
Ashtabula       1,900          17.4         33*          19.3
Painesville      1,381          18.1         25*          14.0
Avon Lake         738          20.3         15*            7.5
Combined       4,019          18.2         73*          40.8

                         Table 2
      Relative risk for specific congenical anomalies in three selected communities including N Ridgeville

                                             Number of defects          risk
Defects                            Observed       expected       ratio
All defects                          109                 56.0           1.95
Central nervous system       17                  5.6            3.02
Cleft plate and lip                10                   6.5            1.53
Genital organs                    16                    8.4            1.90
Clubfoot                              23                    8.2            2.79
all other defects                  43                  27.2            1.58

 

Reference

Infante et al. (1976)

 

 

Method

In a case control study, analysis of incidence rates of central nervous system malformations in infants born to residents of during 1970 - 1974 was studied. (This county contains a PVC production plant).
Result

Incidence rates for CNS malformations for residents are listed in Table 1.  Although the rates of central nervous system defects in infants born to residents of were larger than in control areas, no relationship with parental occupation or residential exposure was found.  The parent’s place of residence at time of infant's conception was determined and distances from the PVC plant were measured for each case and control.  There was no significant difference between the two groups (p>0.4).

                        Table 1
CNS malformation rates for Kanawha County residents, 1970-1974

Defect                              Cases       rate/10,000 births
anencephaly                         23                 14.1
Spina bifida                          15                   9.2
Hydrocephalus                       7                   4.3
Other CNS defects                 2                   1.2
Total CNS defects                47                 28.8
Total white births            16,289

Reference

Edmonds et al. (1978).

 

Method

A case control study of all babies born with CNS effects in was conducted.  The relationship of the cases and controls with two vinyl chloride plants were examined.  For each subject, the distance from the subjects residence and each plant was determined.

Result

There was no relationship between proximity to the vinyl chloride plants and CNS or all birth defects combined.

Reference

Rosenman et al. (1989).

 

Method

Analysis of the incidence of birth defects in infants born to residents  of,during 1966 - 1979 with regard to relation to VC exposure was compared with three other communities,, Baie-Comeau-Hauterive and. A case-control study was also conducted.
Results

Although some data from this study raised the hypothesis of an association between VC in the air and birth defects in the exposed community, such an association can not be substantiated within the sample size available (Table 1).
In the case-control phase of the study, the occupational and residential histories of parents who gave birth to  malformed infants were compared with those of parents of normal infants.  The two groups did not differ in occupational exposure or closeness of residence to the VC polymerization plant.
Birth-defect rates did not differ between school districts with high and low VCM exposure, either for all birth defects or for CNS defects (Table 2).  School districts adjacent to the plant did not differ from the other school districts in numbers of birth defects (total or CNS), nor did districts differ within and beyond a 1-mile radius of the plant.

                            Table 1
Number of malformed children observed in Shawinigan compared with three comparison communities
                                                  expected
                              expected     based on  expected
                             based on    Baie-Comeau based on
Parameter      Shawinigan  Drummondville  Hauterive  Rimouski
Total                    159              102.68**           98.80**    124.08**
CNS                      30                19.69*             18.18*       15.33**
Urogenital             30                19.15*              13.94**      13.14**
* p0.05;  ** p0.01
Values only significant in all three comparison communities is presented.

                            Table 2
  Birth defects between school districts with high and low VCM exposure

                                          high exposure  low exposure    total
births with defects                        87                  70             157
births without defects              2,285             2,125          4,410
births with CNS defects               16                  13               29
births without CNS defects     2,356              2,182         4,538

 

Reference:

Theriault et al. (1983)