Even then, it is difficult to determine a subject location during the entire exposure period, especially when multiple control exposure periods are used.
To better understand how endocrine disruptors alter human reproduction, it would be valuable to design epidemiologic studies with the capacity to address multiple vulnerability periods and time-varying exposures.
This study builds on previous research to examine chemical components of PM2.5 in relation to PTB by investigating a large study area with a wide range of PM2.5 levels and investigating multiple species and exposure periods.
Dextran sodium sulfate (DSS -induced cancer in WT mice typically requires long exposure perioDSS -inducedle cancer of DSS treatment, yet in Mlh1−/− mice, 1% DSS exposure for 1 WTek induces colon neoplasmiceitypicallylatency (by 25 weeks old).
Models including multiple exposure windows suggested short term averaging periods were more relevant than long term averaging periods.
Finally, we performed sensitivity analyses in which we calculated estimates after excluding offspring with multiple exposures across study periods.
If the decline in renal function is reflected in a longer follow-up period with multiple exposure events it could have significant consequences for the routine monitoring of lithium and the follow-up monitoring of patients who have ever had lithium levels >1.0 mmol/L, whether or not they continue with lithium treatment.
Exposures are typically at low concentrations, measurements in water are frequently insufficient, chemicals are present in mixtures, exposure periods are usually long, multiple exposure routes may be involved, and valid biomarkers reflecting the relevant exposure period are scarce.
After all, these problems are characterized by multiple sources, multiple agents, multiple pathways, multiple exposure routes, multiple health effects, long delay periods between cause and effect, cross-bordering scale effects, etc.
