Reproductive hazard

Nitrous oxide Ethylene oxide Toluene Xylene 

---

S. M. Badow and P. M. Sullivan, Reproductive Hazards of Industrial Chemicals, Academic Press, London, 1982, pp. 126—135. 

EPA (1988a) has discussed the results of two reproductive studies in rats. Results of these studies have not been presented in peer-reviewed scientific journals and are not available to the public. If these data become available, they will provide valuable information on the reproductive hazards of methyl parathion. 

Sorokin Y. 1993. Asphyxiants. In Maureen P, ed. Occupational and environmental reproductive hazards A guide for clinicians. Baltimore, MD Williams Wilkins, 253-266. 

Bloom, A. D., Ed. "Guidelines for Studies of Human Populations Exposed to Reproductive Hazards " March of Dimes Birth Defects Foundation New York, 1981, passim. 

APPRAISAL OF CURRENT APPROACHES FOR DETERMINING DEVELOPMENTAL AND REPRODUCTIVE HAZARDS... 

No studies have been conducted to evaluate the reproductive effects of endrin aldehyde or endrin ketone in humans or animals via the inhalation, oral, and dermal routes of exposure. Additional animal studies and further human case studies are needed to determine the potential reproductive hazard and to determine threshold levels for effects that may exist via all three of these routes of exposure. 

Barlow SM, Sullivan FM. 1982. Chlordecone. In Reproductive hazards of industrial chemicals. London, England Academic Press, 212-229. 

NIOSH. 1983. Screening of priority chemicals for potential reproductive hazard. Atlanta, GA National Institute for Occupational Safety and Health, Centers for Disease Control. NTIS Order No. PB85-220143. 

Heinrichs WL. 1983. Reproductive hazards of the workplace and the home. Clin Obstet Gynecol 26 429-436. 

Hamill Py Steinberger E, Levine RJ, Rodriguez-Rigau LJ, Lemeshow S, Avrunin JS The epidemiologic assessment of male reproductive hazard from occupational exposure to TDA and DNT. J Occup Med 24 985-993, 1982... 

Lead exposure can produce a number of other effects. One of the most common effects is on the red blood cells, which results in anemia. The red blood cells become fragile and hemoglobin synthesis is impaired. Changes in the red blood cells and some enzymatic changes were used as a marker for lead exposure. Similar to other metals, lead adversely affects kidney function, but this is now rare with reductions in occupational exposure. Several studies have demonstrated that elevated lead exposure is related to elevated blood pressure levels, particularly in men. There appears to be a weak association between lead exposure and increased incidence of lung and brain cancer. Lead exposure is a reproductive hazard for both males and females. In males, lead affects sperm count and sperm motility, resulting in decreased offspring. 

Reproductive hazard Methoxyethanol, 2-ethoxyethanol, methyl chloride... 

It should also be remembered that fish high in the food chain, such as tuna, swordfish, and shark accumulate toxic substances like mercury or PCBs. Mercury affects the nervous system and is a proven reproductive hazard. Table 13.4 lists examples of marine animals that may be toxic. 

The studies described herein are considered the most definitive currently available for the assessment of developmental and reproductive hazard. The maternal animals in these studies represent the best and most practical model of the human in terms of complexity. 

Laboratory rodents are the animal models most commonly used to identify hazards in reproductive toxicity. Rodents are used because they are small animals, the assay cost is moderate and there is a large database of toxicology information on these species (e.g., dose-response, metabolism, kinetics, etc.). The rat has proven to be a good model for human reproductive hazard evaluation (Francis et al., 1990). 

Bloom AD (1981) Guidelines for reproductive studies in exposed human populations. Guideline for studies of human populations exposed to mutagenic and reproductive hazards. Report of Panel II. White Plains. New York, March of Dimes Birth Defects Foundation, pp 37-110. 

Thomas JA (1981) Reproductive hazards and environmental chemicals a review. Toxic Subst J, 2 318-348. 

Wolff MS (1993) Lactation. In Paul M ed. Occupational and environmental reproductive hazards. Baltimore, Maryland, Williams Wilkins, pp 60-75. 

Methanol highly flammable, toxic by inhalation, ingestion or skin absorption, may be a reproductive hazard, ingestion may be fatal, risk of very serious, irreversible damage if swallowed, exposure may cause eye, kidney, heart and liver damage, chronic or substantial acute exposure may cause serious eye damage, including blindness, irritant, narcotic... 

A much needed book on legal and ethical dilemmas in occupational health is now available (ref. 18). The chapter by Whorton, "Considerations About Reproductive Hazards", is of special interest. The book consists of 38 chapters grouped into five sections occupational safety and health act issues, workers rights and responsibilities, workers compensation, job discrimination, and ethics. 

Reproductive Hazards of Industrial Chemicals (ref. 14) reviews in detail 48 industrial compounds in a consistent format comprising animal studies, human studies, and a summary with evaluation. Animal and human studies are subdivided into sections on pharmacology and toxicology, endocrine and gonadal... 

The February 1987 update of the October 1985 RTECS list of chemicals which cause reproductive hazards, had 6,917 entries. We selected the following T codes T01-T09 (paternal effects), T25 (postimplantation mortality), T31-T59 (effects on embryo or fetus, and specific developmental abnormalities), and T65 (transplacental tumorigenesis). All but the first ones (T01-T09) would fit into a classical definition of teratogens. The paternal effects were included in line with the recommendation by Schardein (vide supra), and also to incorporate the newest data on this long neglected subject. 

In the present article we survey the application of experimental and epidemiologic approaches in the prevention of reproductive hazards in the work place. He also discuss the types of chemicals that women are exposed to and the changing role of women in the labor force. 

In the future the nature of chemical exposure has been predicted to change. The level of exposures will decrease, but at the same time simultaneous exposure to many chemicals with low concentration will become more general as the usage of chemicals in the society is growing continuously. In western countries, approximately 200-1000 new chemicals (in quantities of 500 kg or more) are developed and introduced into the marketplace every year. A potential reproductive hazard, in addition to chemicals, is ionizing and nonionizing radiation, the use of which will also grow in future work environment. It has been estimated that internationally the number of workers exposed to radiation will increase over 100 % by the year 2000. 

It should be emphasized that this kind of comparison is quite theoretical, and it does not provide absolute unsafe exposures, nor does it specify safe levels. However, with the present understanding of the animal experiments it would appear prudent to lower the TLV values for the compounds for which the human exposure may be up to 1/100 of the effective human dose. Even though the extrapolation from animal tests is compounded by uncertainties, the revision of the hygienic standards concerning the pregnant worker appears justifiable in such cases. With ever-increasing female participation in the work force, more emphasis should be placed on reproductive hazards and their prediction, in the absence of adequate epidemiologic data, from experimental results. 

Reproductive hazards in the workplaces can be identified through epidemiologic research, outcomes such as spontaneous abortions and malformations require large sample sizes that cannot usually be collected from single workplaces. Several workplaces need to be pooled and a coordinated effort is required in the execution of the studies. However, a systematic follow-up of the rates of spontaneous abortions and malformations by industrial physicians may offer clues to reproductive hazards. On other outcomes, such as birthweight of children and sperm abnormalities in exposed men, smaller sample sizes are required but many types of confounding factors may exist that impede the interpretation of the results. 

---