Exposure, infant

Infants with high intrauterine exposure had higher scores on the BNBAS excitabihty cluster than infants with low exposure. Infants with a high BNBAS excitability score had poorer tone and motor movement, were more irritable and hard to console, and had difficulties in self-quieting. 

As methylmercury readily crosses the placental barrier, marked developmental toxicity has been observed in both humans and animals after gestational exposure. Infants born to mothers during the Minamata breakout appeared normal at birth. 

Children are expected to be exposed to methyl parathion by the same routes that affect adults. Small children are more likely to come into contact with methyl parathion residues that may be present in soil and dust both outside and inside the home, due to increased hand-to-mouth activity and playing habits. Methyl parathion has been detected in a few samples of breast milk, indicating potential for exposure of nursing infants. However, available data are not adequate for determination of the importance of this route of child exposure. 

Certain characteristics of the developing human may increase exposure or susceptibility while others may decrease susceptibility to the same chemical. For example, although infants breathe more air per kilogram of body weight than adults breathe, this difference might be somewhat counterbalanced by their alveoli being less developed, which results in a disproportionately smaller surface area for alveolar absorption (NRC 1993). 

Exposures of Children. Data need to be developed to properly assess the exposure of infants who eat processed baby foods containing residues of pesticides such as endosulfan. Several studies have estimated exposure based on endosulfan concentration found in foods typically eaten by infants however, no studies that directly studied infant exposure could be located. Attention should also be given to infant formulas and to the tap water used to prepare infant formulas from condensed or powdered forms. More data are also required to properly assess endosulfan exposure to children who live, play, or attend school near farmlands that are treated with endosulfan. Maps that catalog endosulfan use on crops and present average application rates would better allow an assessment of the potential for children in farming communities to be exposed. The possibility that farming parents work clothes and shoes may carry endosulfan residues into the home also should be studied. In addition, home use of endosulfan, which may result in exposure of children, needs to be investigated. 

Public concern about PBDE levels in the environment was heightened when it was shown that a sharp increase in the concentration of certain PBDEs had occurred in human breast milk over only a 10-year period (Meironyte et al. 1999 Noren and Meironyte 2000), and the levels of exposure in some infants and toddlers were similar to those shown to cause developmental neurotoxicity in animal experiments (Costa and Giordano 2007). As a result of these concerns, the majority of commercial PBDE mixtures have been banned from manufacture, sale, and use within the European Union. 

SETCHELL KDR, ZIMMER-NECHEMIAS L, CAI J and HEUBI J E (1997) Exposure of infants to phyto-oestrogens from soy-based infant formula. Lancet. 350 (9070) 27-21. 

Later in intra-uterine life, the human infant is susceptible to early chemical prompting, but again the affector route is not known with certainty. Neonatal discrimination in favour of familiar (maternal) amniotic fluid is demonstrable, suggesting that the foetus already has active chemosensory capacities (Schaal, 1998). Smell and taste are operative in the near full-term foetus since it shows detection of about 120 mg/day maternal intake of anethole (as anise condiments) within a few days before parturition this exposure induced subsequent preferential responses by babies to anethole (Schaal et ai, 2000). The human neonate is not likely to have its organ as a fully functioning chemosensor,... 

With the increased use of PCP by young women, pediatricians have begun to identify the newborn s neurobehavioral symptoms after In utero exposure. In 1980, Golden et al. were the first to document the placental transfer of PCP in humans and to describe the resulting neurobehavioral symptoms. They reported on one infant whose mother had smoked an average of six joints per day of marijuana dusted with PCP. The behaviors emerging shortly after birth... 

All infants developed deviant neurobehavioral symptoms within the first 24 hours of life. Most commonly, the neonates were found to have symptoms of irritability, tremors, and hypertonicity. Bizarre eye movements and staring spells were seen in 25 percent of infants. Poor sucking, lethargy, diarrhea, and facial twitching, symptoms commonly associated with prenatal opiate exposure, were seen infrequently in these PCP-addicted infants. 

Information from wel1-control 1 ed animal studies that focus on the effects of prenatal exposure to single and polydrug use will be of great value. Further evaluation of the fine motor movements that appear to be clearly neurological ly deviant in the PCP-exposed infants is essential. The emerging socialization skills during the second year of life also need more detailed evaluations. 

Most health care workers are at risk for exposure to many diseases in the normal course of their work. Additionally, health care workers may transmit vaccine-preventable diseases to their patients. At the time of employment and on a regular basis, health care workers should be screened for immunity to measles, rubella, and varicella if found to be non-immune, the measles, mumps, and rubella, and varicella vaccines should be administered. The hepatitis B series should be given if not already completed. Tetanus should be updated and given every 10 years. Health care personnel in hospitals and ambulatory settings with direct patient contact should receive Tdap if not already received an interval as short as 2 years from the last tetanus-containing vaccine should be used. Priority for receiving Tdap should be given to personnel with direct contact with infants less than 12 months of age. 

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