Contamination Of Breast Milk Research Articles

Community-acquired Methicillin-Resistant Staphylococcus aureus Bilateral Acute Dacryocystitis in a Neonate

Dear Editor, Bilateral acute dacryocystitis in neonates is a rare condition with very few cases described in literature.[1–3] We present a case of bilateral acute dacryocystitis secondary to congenital nasolacrimal duct obstruction (CNLDO), caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). This was the first case of bilateral acute dacryocystitis secondary to CNLDO, caused by CA-MRSA in our Medline search result, hence we report the case. A 12-day-old newborn boy (delivered at home) with bilateral acute dacryocystitis since two days was referred to us by his pediatrician. The mother had taken antibiotics for bilateral MRSA mastitis during pregnancy. Ophthalmic examination revealed bilateral lacrimal sac abscess. The size of the lacrimal sac abscess was approximately 1.5 × 1.5 cm OD and 1.5 × 1.0 cm OS [Fig. 1a]. Mild compression of the lacrimal sac resulted in regurgitation of purulent discharge from the lower puncta. Both the eyelids showed edema and erythema. The remainder of his ocular examination was normal. Blood and conjunctival swab were sent for culture and sensitivity.Figure 1a: The clinical photograph of the face at the time of presentation showing bilateral acute dacryocystitis with lacrimal abscess formationThe newborn was hospitalized and intravenous amoxicillin/clavulanic acid and amikacin were started. Over the next 12 h, swelling and redness increased with bilateral external fistula formation [Fig. 1b]. Bilateral incision and drainage of the abscess was performed under general anesthesia. Approximately 2 ml of thick, yellowish collection was aspirated from each site and sent for culture. Gram stain revealed Gram-positive cocci, fibrinous exudates, and both inflammatory and red blood cells. Blood culture was negative. Swab cultures demonstrated Staphylococcus aureus, sensitive to vancomycin, clindamycin and rifampicin, but resistant to methicillin, amoxicillin, amikacin and ciprofloxacin. Mother's breast milk was sterile but recent breast swab culture revealed same organism with identical antibiotic susceptibility. The patient was switched to vancomycin. Topical 5% vancomycin solution was given QID. The lacrimal swelling and erythema resolved completely over the course of two days [Fig. 1c]. The mother was also re-treated for mastitis. Probing and irrigation of the nasolacrimal duct was performed in both eyes two weeks after presentation which resolved CNLDO. Patient was free from lacrimal symptoms at six month's follow-up.Figure 1b: The clinical photograph showing increased inflammatory signs with external fistula formation OU even after 12 hours of hospitalization and intravenous antibioticsFigure 1c: The clinical photograph showing reduced lacrimal and periocular swelling on day-2 postoperativelyOphthalmic CA-MRSA infections have been previously reported.[4] Neonates may acquire CA-MRSA vertically from their mother's contaminated breast milk or by skin-to-skin contact.[5] CA-MRSA is resistant to mainly beta-lactam antibiotics e.g. penicillin and cephalosporin. On the other hand, Hospital-acquired MRSA is resistant to multiple antibiotics.[4] In the present case, organisms were not only resistant to beta-lactams but also to quinolones and aminoglycosides. Recently, multi-drug-resistant CA-MRSA has also been observed.[6] The probable source of infection, in the present case, was maternal breast skin, which reached the nasolacrimal system via skin-to-skin contact during breast feeding. Isolation of MRSA with identical antibiotic susceptibility, from mother's breast swabs, conjunctival sac as well as purulent material from lacrimal sac, supports a cause-effect relationship of vertically acquired CA-MRSA in the present case. To avoid treatment delay, vertical transmission of CA-MRSA should be suspected even in cases of acute dacryocystitis involving otherwise healthy newborns with positive family history of MRSA infection.

Regional variation and possible sources of brominated contaminants in breast milk from Japan

This study focuses on the regional trends and possible sources of brominated organic contaminants accumulated in breast milk from mothers in southeastern (Okinawa) and northwestern (Hokkaido) areas of Japan. For persistent brominated flame retardants, polybrominated diphenyl ethers (PBDEs; major components, BDE-47 and BDE-153) were distributed at higher levels in mothers from Okinawa (mean, 2.1 ng/g lipid), while hexabromobenzene (HeBB) and its metabolite 1,2,4,5-tetrabromobenzene were more abundantly detected in mothers from Hokkaido (0.86 and 2.6 ng/g lipid), suggesting that there are regional differences in their exposure in Japan. We also detected naturally produced brominated compounds, one of which was identified as 2′-methoxy-2,3′,4,5′-tetrabromodiphenyl ether (2′-MeO-BDE68) at higher levels in mothers from Okinawa (0.39 ng/g lipid), while the other was identified as 3,3′,4,4′-tetrabromo-5,5′-dichloro-2,2′-dimethyl-1,1′-bipyrrole in mothers from Hokkaido (0.45 ng/g lipid). The regional variation may be caused by source differences, i.e. southern seafood for MeO-PBDEs and northern biota for halogenated bipyrroles in the Japanese coastal water.

WHEN POLLUTION GETS PERSONAL: DEVELOPING PROTOCOLS FOR BIOMONITORING RESULTS COMMUNICATION WITH INPUT FROM STUDY PARTICIPANTS

Background: Advances in biomonitoring methods have enabled environmental health scientists to measure ever-lower concentrations of environmental contaminants in human blood, urine, breast milk, and other tissues. Yet our ability to detect chemicals in humans has rapidly outpaced our capacity to interpret what personal exposure results mean for health effects, sources or toxicity. This situation raises ethical and scientific challenges related to reporting biomonitoring results to individual study participants and their communities. California’s Biomonitoring Program is required by law to provide individual chemical exposure results to those participants who want them. Methods: We developed individual report-back materials that are scalable to a statewide biomonitoring program involving participants from diverse cultural backgrounds and literacy and numeracy levels. We recruited study participants from the Chemicals in Our Bodies Project, a biomonitoring study conducted by UC Berkeley, UCSF and Biomonitoring California, which is testing for chemicals in pregnant mothers and their newborn babies. Upon recruitment, study participants were asked to participate in usability testing of prototype report-back materials that assessed whether and how messages about chemical exposures and scientific uncertainty regarding health effects and sources are understood and interpreted. Results: Participants valued getting their personal biomonitoring results and were able to identify their exposure levels from the text and graphs provided in the prototype materials. Participants understood the scientific uncertainty regarding the implications of exposures for health effects. Key challenges were distilling results from the large number of chemical analytes tested and communicating the meaning of reference levels. Conclusion: Although medical ethics have favored reporting only clinically significant biomonitoring results, public policy and community concern regarding the ubiquity of chemical exposures is beginning to broaden the ethical focus toward participants’ right-to-know. This shift will necessitate more research on developing effective report-back protocols that are accessible and transparent to linguistically and culturally diverse groups.

PCDD/Fs and dioxin-like PCBs in human milk and estimation of infants’ daily intake: A review

This paper reviews the recent scientific literature on PCDDs, PCDFs and dioxin-like PCBs in human milk. All the papers reporting levels of these contaminants in human breast milk published from January 2000 to January 2009 and available on the www.sciencedirect.com web site were identified and included. The aim was (1) to study levels of PCDDs, PCDFs and PCBs in human milk in mothers from different geographical areas and assess infant exposure to these contaminants; (2) to study the effect of variables such as the mother’s age, number of deliveries, dietary and smoking habits and her own nutrition in infancy, and the environment, on levels of the contaminants in breast milk; (3) to study time patterns, and (4) to identify data gaps.

Contamination of Human Breast Milk by Persistent Organic Pollutants (POPs) in Developing Asian Countries

Contamination of Human Breast Milk by Persistent Organic Pollutants (POPs) in Developing Asian Countries

Detection of aflatoxin M1 in human breast milk and raw cow's milk in Istanbul, Turkey.

This survey was undertaken to determine the extent of aflatoxin M1 (AFM1) contamination in human breast milk and raw cow's milk in Istanbul, Turkey. Samples of human and raw cow's milk were collected randomly and analyzed for AFM1 using an enzyme-linked immunosorbent assay and high-performance liquid chromatography with fluorescence detection in which the samples were cleaned up with immunoaffinity columns. In this study, AFM, was detected in 8 (13.1%) of 61 human breast milk samples examined (mean +/- SD level, 5.68 +/- 0.62 ng/liter; range, 5.10 to 6.90 ng/liter) and 20 (33.3%) of 60 raw cow's milk samples examined (range, 5.40 to 300.20 ng/liter). Five (8.3%) of the positive raw cow's milk samples had AFM1 levels (153.52 +/- 100.60 ng/liter; range, 61.20 to 300.20 ng/liter) that were higher than the maximum tolerance limit (0.05 ppb) stipulated by regulations in Turkey and some other countries.

PCB-containing wood floor finish is a likely source of elevated PCBs in residents' blood, household air and dust: a case study of exposure

BackgroundPolychlorinated biphenyls (PCBs) are persistent pollutants identified worldwide as human blood and breast milk contaminants. Because they bioaccumulate, consumption of meat, fish, and dairy products predicts human blood concentrations. PCBs were also used widely in building materials, including caulks and paints, but few studies have evaluated the contribution of these exposures to body burden.MethodsIn an earlier study, we detected PCBs in indoor air in 31% of 120 homes on Cape Cod, MA. Two of the homes had much higher concentrations than the rest, so we retested to verify the initial finding, evaluate blood PCB concentrations of residents, and identify the PCB source.ResultsAir and dust concentrations remained elevated over 5 years between initial and follow-up sampling. Blood serum concentrations of PCBs in residents of the homes were generally elevated above the 95th percentile of a representative sample of the US population. Serum concentrations in residents and air and dust concentrations were especially high in a home where a resident reported use of PCB-containing floor finish in the past, and where the floor of one room was sanded and refinished just prior to sample collection.ConclusionThis case-study suggests that PCB residues in homes may be more significant contributors to overall exposure than diet for some people, and that use of a commercially-available PCB-containing wood floor finish in residences during the 1950s and 1960s is an overlooked but potentially important source of current PCB exposure in the general population.

Environmental Health: Chemicals in Breast Milk

Although breast milk is recognized by doctors, public health officials, and scientists as the best first food for an infant, it is not pure. Many synthetic chemicals released into the environment, intentionally or not, can be found in breast milk. Chemicals such as famous â¬Sbad actorsâ¬? like dichloro-diphenyl-trichloroethane, commonly known as DDT, and polychlorinated biphenyls (PCBs), as well as less well-known substances such as flame retardants (polybrominated diphenyl ethers, or PBDEs), have been detected in human breast milk around the world. Many of those synthetic chemicals are known or suspected causes of cancer, and they have been linked to other health problems such as diabetes, reproductive disorders, and impaired brain development. The health benefits of breastfeeding far outweigh the possible negative effects of chemical contaminants in breast milk, but the presence of those chemicals remains a cause for concern among health officials, individuals, and the companies whose products or manufacturing process release toxins into our environment.

Assessing levels of contaminants in breast milk: methodological issues and a framework for future research

To assess the scale of the possible exposure by the breast-fed infant to potentially harmful substances in breast milk, methodologically robust studies are essential. Many studies in this field, however, do not report details of crucial issues such as recruitment and milk sampling. The aims of the study reported here were to develop robust methods for the study of contaminants in breast milk, and to develop a framework for future research and population monitoring. Three cohorts of women and babies were recruited by midwives from five sites in northern England. Cohort 1 (cross-sectional, n = 322) were asked to provide two milk samples, one at one week following birth and one at a subsequent time point. Cohort 2 (longitudinal, n = 54) were asked to provide five samples at specified time points over the first 12-16 weeks after birth. Cohort 3 (convenience, n = 18), mothers of babies in the Special Care Unit, were asked to donate surplus breast milk. A novel method of analysing fat concentration in small volumes was developed and tested. A randomly selected set of samples from different donors and stages of lactation was screened for organochlorine pesticide residues, polychlorinated biphenyls, dioxins/furans, phthalates and heavy metals. A total of 453 samples were donated. Cohort 3 was the least successful route of recruitment. Cohorts 1 and 2 combined were most representative of the population. Sample collection, transport and storage procedures, and the collection of data on life style and diet, were robust and acceptable to women. Midwifery involvement in recruitment was an essential component. This study offers a framework both for the conduct of future research studies, and for the establishment of regional and national monitoring mechanisms for contaminants in breast milk. Similar work on contaminants in formula as fed to babies is needed to inform risk assessment methods.

Growth and survival of Enterobacter sakazakii in human breast milk with and without fortifiers as compared to powdered infant formula

Enterobacter sakazakii infections often involve debilitated neonates consuming contaminated reconstituted powdered infant formula. There is the possibility that expressed human breast milk can become contaminated with E. sakazakii in the hospital or home setting and through the use of contaminated breast milk fortifiers. In addition, although breast milk has been shown to have some antimicrobial effects, this has not been extensively researched in regards to E. sakazakii. Thus, we examined the survival and growth of 9 strains of E. sakazakii in breast milk, human breast milk with fortifiers and powdered infant formula at 10, 23 and 37 °C. The average generation times for clinical, food and environmental isolates in breast milk were 0.94 ± 0.04, 0.75 ± 0.04 and 0.84 ± 0.04 h at 23 °C; and 0.51 ± 0.03, 0.33 ± 0.03 and 0.42 ± 0.03 h at 37 °C, respectively. E. sakazakii was able to survive up to 12 days in breast milk with fortifiers at 10 °C. However, its average generation times among replicates and isolate sources ranged from 11.97 ± 3.82 to 27.08 ± 4.54 h in breast milk at 10 °C. Interestingly, average generation times in breast milk with fortifiers at 23 °C (0.83 ± 0.05, 0.93 ± 0.06 and 0.96 ± 0.06 h) and 37 °C (0.41 ± 0.04, 0.51 ± 0.05 and 0.54 ± 0.05 h) were longer than in powdered infant formula and breast milk at the same temperatures, indicating that human breast milk fortifiers may have an inhibitory effect on the growth of E. sakazakii. However, the intrinsically ascribed antimicrobial properties of breast milk do not appear to inhibit the growth of this foodborne pathogen in-vitro.

Breast-Feeding and Silicone Implants

Despite the overwhelming advantages of breast-feeding, there is a persistent concern that maternal exposure to chemical contaminants may result in contamination of breast milk and have an effect on the child's growth and development. A parallel concern regarding lactation in women with silicone implants over the past years has led to confusion and anxiety relating to the potential risks to the child. The author reviewed the facts and issues as he knows them, including biomaterials, lactation toxicology, and a previous study where no difference was found in silicon (a proxy measurement of silicone) in women breast-feeding with silicone implants and those without. In the author's previous study, he compared women with implants to women without implants as controls and showed that mean silicon levels were not significantly different in breast milk (55.45 +/- 35 and 51.05 +/- 31 ng/ml, respectively) or in blood (79.29 +/- 87 and 103.76 +/- 112 ng/ml, respectively). However, silicon levels in alternative methods of infant nutrition were much higher. The mean silicon level measured in store-bought cow's milk was 708.94 ng/ml, whereas that for 26 brands of commercially available infant formula was 4402.5 ng/ml. In this review, the author looked only at silicon/silicone and did not address other potential contaminants that may be associated with silicone gel or the elastomer shell. This report may provide plastic surgeons and other healthcare workers with information regarding silicon/silicone for discussion with women with gel implants who are contemplating breast-feeding.

Astonishingly high contamination of human breast milk and body fat with mineral paraffins: should we worry?

Problem: Although widely used in cosmetics and the food processing industry the toxicologic effects of mineral paraffins are widely unknown. According to scientific literature specific mineral hydrocarbons lead to pathologic tissue reactions. Method: During the elective sectio caesarea of 144 probands 1g of abdominal fat tissue was sampled. On the 4. and 20. postpartal day 5–15 mL of breast milk where collected. The probands filled in a detailed questionnaire about personal data, use of cosmetic products and nutritional habits. A specialized liquid-gas-chromatographic method was used to analyze the mineral paraffin content of all samples. Results: An average mineral paraffin concentration of 60.7mg/kg (10–360mg/kg) was found. 80% of the concentrations ranged from 30 to 100mg/kg. Between the 4. and 20. postpartal day the mineral paraffin concentration decreased from an average of 47.99mg/kg (9–355mg/kg) to 26.13mg/kg (5–285mg/kg). Astonishingly the composition of the hydrocarbons was widely identical across all samples with a chromatographic center at C23/C24 and a chain length of C17 to C32. A multivariate analysis showed, that the mineral paraffin concentration in fat tissue samples correlated with the age (p<0.001), the BMI (p=0.014) and the use of hand lotions (p=0.003). No correlation with nutritional habits was found. Conclusion: Mineral paraffins where found to contaminate the human body significantly. During lactation mineral paraffins are transferred to the baby. The nearly identical composition in all analyzed fat tissue and breast milk samples suggests that a strict selection of mineral paraffins during accumulation took place.

Beneficial Effects of Breastfeeding on Cognition Regardless of DDT Concentrations at Birth

The authors previously reported that intrauterine exposure to background concentrations of p,p'-dichlorodiphenyltrichloroethane (DDT) reduces cognitive performance among preschoolers. Breastfeeding has been associated with both increased exposure to certain pollutants during infancy and better performance on cognitive tests. Thus, the authors examined the role of breastfeeding in cognitive function among preschoolers, taking prenatal DDT exposure into account. Two birth cohorts in Spain (Ribera d'Ebre and Menorca) were recruited between 1997 and 1999 (n = 391). Infants were assessed at age 4 years using the McCarthy Scales of Children's Abilities. Levels of organochlorine compounds were measured in umbilical cord serum. Information on type and duration of breastfeeding was obtained by questionnaire when the children were 1 year of age. Children who were breastfed for more than 20 weeks had better cognitive performance regardless of their in utero exposure to DDT. A linear dose response between breastfeeding and cognition was observed in all DDT groups (for children highly exposed to DDT, adjusted beta = 0.30 (standard error, 0.12) per week breastfed). Despite the possibility of harm from environmental contaminants in breast milk, breastfeeding for long periods should still be recommended as the best infant feeding method.

Assessment of the exposure of breast milk to persistent organic pollutants in Latvia

According to the National Implementation Plan on persistent organic pollutants (POP) for the years 2004–2020 the situation on POP was actualised in Latvia. The aim of the study was to assess the contamination of breast milk with polychlorinated biphenyls (PCB), polychlorinated dibenzodioxins, dibenzofurans (PCDD/PCDF) and some pesticides. Breast feeding mothers (together 30) were selected from probably polluted area, and a control group on the basis of WHO criteria for donor selection. The concentration of POP in milk was detected by gas chromatography with HRGC/HRMS, HRGC/ECD and GC/ECD detection after extraction of milk fat and purification. The results of the survey show comparability of both groups in age, weight, habits, occupation as well as age of the children and the weight at birth and at the time of collecting the samples. PCB were not observed in 15.9%, PCDD/PCDF in 6.6% and pesticides in 14% analyses of the target group and in 26.3%, 7% and 8.6% analyses correspondingly of the control group. The concentration of 18 detected PCB, 17 detected PCDD/PCDF and 8 chlorinated pesticides and its metabolites varied in wide range and the differences of mean values within groups were not statistically significant ( p>0.05). The concentration of POPs corresponds to lowest levels detected in European countries. The concentration of dioxine-like PCBs and PCDD/PCDF according to toxicity equivalents does not exceed the WHO accepted level of 15 TEQ pg/g milk fat.

Adverse health effects of children's exposure to pesticides: What do we really know and what can be done about it

Children may be exposed to pesticides in several ways, such as by transplacental transfer during foetal life, by intake of contaminated breast milk and other nutrients, or by contact with contaminated subjects and areas in the environment such as pets treated with insecticides, house dust, carpets and chemically treated lawns and gardens. Exposure early in life, and particularly during periods of rapid development, such as during foetal life and infancy, may have severe effects on child health and development by elevating the risk of congenital malformations, cancer, malabsorption, immunological dysfunction, endocrine disease, and neurobehavioural deficiencies. As pesticides can also interfere with parental reproductive health, exposure of parents may have consequences for the offspring leading to reduced chance of male birth and increased risk of childhood cancer. Current knowledge about tolerable levels and consequences of toxic exposure to pesticides during human development is rather scarce. Owing to the high risk of exposure to pesticides, particularly in less developed countries, further elucidation by well-controlled epidemiological studies in this field it is urgently needed. The Policy Interpretation Network on Children's Health and Environment (PINCHE), which is financed by the EU DG research has suggested actions against pesticide exposure. They have been presented and discussed in this paper. Several suggestions of PINCHE concerning action needed regarding pesticides were presented in the paper.

Determinants of aflatoxin M1 in breast milk in a selected group of Egyptian mothers

In Egypt, there is a paucity of biomarker data on aflatoxin (AF) exposure. The study assessed the level and frequency of breast milk AFM1 as a biomarker of maternal exposure. Breast milk samples were collected from a selected group of 388 Egyptian lactating mothers of children attending the New El-Qalyub Hospital, Qalyubiyah governorate, Egypt, during May–September 2003. Following aflatoxin extraction, AFM1 levels were assessed by high-performance liquid chromatography (HPLC) with fluorescence detection. Approximately 36% of mothers tested positive for AFM1 (median 13.5 pg ml−1, interquartile range (IQR) 10.27–21.43). Non-working status (p = 0.018, odds ratio (OR) = 2.87), obesity (p = 0.004, OR = 3.01), high corn oil consumption (p = 0.002, OR = 2.21), number of children (>1) (p = 0.025, OR = 1.99), and early lactation stage (<1 month) (p = 0.028 OR = 3.57), contributed to the occurrence of AF in breast milk. AFM1 contamination of breast milk was frequent, albeit at moderate levels. Growth and development of the infant is rapid and thus it is possible that AF exposure through breast milk has a significant health effect.

Contamination status of persistent organochlorines in human breast milk from Japan: Recent levels and temporal trend

Contamination levels of persistent organochlorines (OCs) such as polychlorinated dibenzo- p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB), and chlordane compounds (CHLs) was examined in human breast milk collected during 2001–2004 from Fukuoka prefecture in Japan. The concentrations of OCs such as dioxins and related compounds, DDTs, CHLs and HCB in human breast milk from primiparae were comparable to or slightly higher than the data obtained during 1998, indicating that the levels of these contaminants in Japanese human breast milk have not decreased since 1998 and Japanese are continuously exposed to these chemicals, presumably via fish intake. In addition, OC levels in human breast milk from primiparae were significantly higher than those from multiparae, implying elimination of OCs via lactation. Furthermore, significant positive correlations were observed between levels of OCs in human breast milk and the age of primiparae. These results indicate that the mothers with higher age may transfer higher amounts of OCs to the first infant than to the infants born afterwards through breast-feeding, and hence the first born children might be at higher risk by OCs.

Environmental Contaminants in Breast Milk

Toxic environmental contaminants can be transferred from mother to infant via breastfeeding. Persistent organic pollutants (POPs) are a family of lipophilic stable chemicals that bioaccumulate in adipose tissue and create a lasting toxic body burden. Breastfeeding provides a significant source of exposure to POPs early in human life, the effects of which are unknown, and is the subject of a growing body of research. Despite the possibility of harm from environmental contaminants in breast milk, breastfeeding is still recommended as the best infant feeding method. This article reviews what is known about POPs in breast milk and their effect on infant development to inform clinicians about the issue, provide recommendations for practice, and promote environmental and public health policies that reduce human exposure to harmful pollutants.

First Report of Salmonella enterica Serotype Panama Meningitis Associated with Consumption of Contaminated Breast Milk by a Neonate

Salmonella enterica serotype Panama is capable of causing severe infection in children and is often transmitted via contaminated food. Here, we present the first documented case of serotype Panama infection that was acquired through the consumption of contaminated breast milk. The mother excreted the organism asymptomatically for at least 2 weeks.

Human Breast Milk Contamination with Phthalates and Alterations of Endogenous Reproductive Hormones in Infants Three Months of Age

Phthalates adversely affect the male reproductive system in animals. We investigated whether phthalate monoester contamination of human breast milk had any influence on the postnatal surge of reproductive hormones in newborn boys as a sign of testicular dysgenesis.DesignWe obtained biologic samples from a prospective Danish–Finnish cohort study on cryptorchidism from 1997 to 2001. We analyzed individual breast milk samples collected as additive aliquots 1–3 months postnatally (n = 130; 62 cryptorchid/68 healthy boys) for phthalate monoesters [mono-methyl phthalate (mMP), mono-ethyl phthalate (mEP), mono-n-butyl phthalate (mBP), mono-benzyl phthalate (mBzP), mono-2-ethylhexyl phthalate (mEHP), mono-isononyl phthalate (miNP)]. We analyzed serum samples (obtained in 74% of all boys) for gonadotropins, sex-hormone binding globulin (SHBG), testosterone, and inhibin B.ResultsAll phthalate monoesters were found in breast milk with large variations [medians (minimum–maximum)]: mMP 0.10 (< 0.01–5.53 μg/L), mEP 0.95 (0.07–41.4 μg/L), mBP 9.6 (0.6–10,900 μg/L), mBzP 1.2 (0.2–26 μg/L), mEHP 11 (1.5–1,410 μg/L), miNP 95 (27–469 μg/L). Finnish breast milk had higher concentrations of mBP, mBzP, mEHP, and Danish breast milk had higher values for miNP (p = 0.0001–0.056). No association was found between phthalate monoester levels and cryptorchidism. However, mEP and mBP showed positive correlations with SHBG (r = 0.323, p = 0.002 and r = 0.272, p = 0.01, respectively); mMP, mEP, and mBP with LH:free testosterone ratio (r = 0.21–0.323, p = 0.002–0.044) and miNP with luteinizing hormone (r = 0.243, p = 0.019). mBP was negatively correlated with free testosterone (r = −0.22, p = 0.033). Other phthalate monoesters showed similar but nonsignificant tendencies.ConclusionsOur data on reproductive hormone profiles and phthalate exposures in newborn boys are in accordance with rodent data and suggest that human Leydig cell development and function may also be vulnerable to perinatal exposure to some phthalates. Our findings are also in line with other recent human data showing incomplete virilization in infant boys exposed to phthalates prenatally.