The children are followed-up to the age of 2 years to deter­mine long term effects of pre- and postnatal environmental exposures.

Exposure of children to ETS. Postnatal children exposure to ETS at 12, and 24 months after birth is assessed. From the children urine sample and saliva samples from mothers who declare smoking abstinence are collected. The saliva and urine cotinine level is analysed using high performance liquid chromatography coupled with tandem mass spectrometry/positive electrospray ionization (LC-ESI+MS/MS) and isotope dilution method.

Exposure of children to PAH. The HPLC technique is used for the analysis of the level of 1-hydroksypyrene in urine as the biomarker of PAH exposure (children at 12 and 24 months of age).

Exposure of children to phthalates Phthalate exposure is determined by measuring 11 phthalate metabolites (MEP, MiBP, MnBP, 3OH-MnBP, MBzP, MEHP, 5OH-MEHP, 5oxo-MEHP, OH-MiNP, oxo-MiNP, and MnOP) in the urine collected from children at the 24th month of age. The analysis is performed using the HPLC–MS/MS method.

Exposure to indoor allergens, endotoxins and glucans. The analyzis is covered approx. 50 family homes of children. The settled dust is collected from floors in leaving rooms and in children beds (mattresses and blankets). To determine allergens concentrations in dust samples, the commercially available enzymelinked immunosorbent assey (ELISA) kits ispplied according to the protocol.To determine endotoxins and (1→3)-β-D-glucans concentrations the LAL test will be applied. The questionnaire study is performed among parents in order to obtain the data about demographic factors and home conditions.

Questionnaires conducted with mothers 12, and 24 months after delivery. Mothers of all children are interviewed. The questionnaires investigate the children’s health and development, the nutrition of the small child and their contacts with other children. The smoking status of the parents and other potential sources of children’s ETS exposure are identified. Information about proximity to heavy traffic is inquired. Additionally the information from the closets to his/her place of living air pollution monitoring station is collected. Exposure to other environmental factors including domestic animals, home dust, household cleaning agents and indoor used pesticides is evaluated by the questionnaire.

Determination of the prevalence of the upper and lower respiratory tract infections, middle ear diseases and allergy among the child. The incidence of the upper and lower respiratory tract infections, middle ear diseases and symptoms of allergy among the child is identified based on the detailed interview with the mothers in 12 and 24 month after child birth. This interviews is conducted by paediatricians. For each child upper and lower respiratory tract infections (tonsillitis, laryngitis, bronchitis and pneumonia), as well as middle ear diseases and allergy to food and inhalant allergens is identified based on the review of their medical charts. The duration of each infection and disease, medications taken and hospitalization is identified. The current health status of the child and child’ anthropometry (high, weight) is performed by pediatrician.

Determination of the neurodevelopment of the children. BSID-III is used for assessment of child neurodevelopment. The tests is scheduled on 12 and/ 24 months of life and is conducted by psychologist or child development specialist. The test assesses five developmental areas of the child: cognitive, motor (fine and gross motor), language (receptive, expressive), social-emotional and adaptive behavior.