A national survey of persistent, bioaccumulative, and toxic (PBT) pollutants in the United States milk supply

Abstract

This study measured 21 persistent, bioaccumulative, and toxic (PBT) pollutants in the US milk supply. Since milk fat is likely to be among the highest dietary sources of exposure to PBTs, it is important to understand their levels in this food. Nationwide samples were collected from 45 dairy plants in July of 2000 and again in January 2001. The levels of all chemicals in the chlorobenzene, pesticide and other halogenated organic groups were determined to be below their detection limits in all samples. National averages were computed for 11 chemicals or chemical groups found above the detection limits. The national average CDD/CDF and PCB TEQ concentrations were 14.30 and 8.64 pg/l, respectively, for a total of 22.94 pg/l. These levels are about half the values found in a similar study conducted in 1996. If this difference is in fact indicative of declining milk levels and assuming exposure levels from nondairy pathways have remained the same over this time period, this would result in an overall decrease in adult background dioxin exposure of 14%. Six PAHs were detected with national averages ranging from 40 to 777 ng/l. Cadmium concentrations ranged from 150 to 870 ng/l with a national average of 360 ng/l. Lead concentrations were consistently higher than those of cadmium, ranging from 630 to 1950 ng/l with a national average of 830 ng/l. PAHs showed the strongest seasonal/geographic differences, with higher levels in winter than summer, north than south and east than west. Average adult daily intakes from total milk fat ingestion were computed for all detected compounds and compared to total intakes from all pathways: CDD/CDF/PCB TEQs: 8 vs. 55 pg/day, PAHs: 0.6 vs. 3 mg/day, lead: 0.14 vs. 4-6 mg/day, and cadmium: 0.06 vs. 30 mg/day.

Exposures among Pregnant Women near the World Trade Center Site on 11 September 2001

“…Other detected dioxins and dibenzofurans found by us (1,2,3,6,7,8-hexachlorodibenzodioxin, 1,2,3,4,6,7,8-heptachlorodibenzodioxin/furan, and OCDD) are also widely detected and are the highest detected congeners in breast milk (Focant et al 2002; Glynn et al 2001; Schaum et al 2003; Schecter et al 2002). Their relative proportions (i.e., OCDD > 1,2,3,4,6,7,8-heptachlorodibenzodioxin > 1,2,3,6,7,8-hexachlorodibenzodioxin) are similar to those among the WTC women in our cohort, even where levels were much higher (Yang et al 2002).…”

Estimating perchlorate exposure from food and tap water based on US biomonitoring and occurrence data

“…Indoor air levels of 1,4-DCB may exceed outdoor levels when moth repellents or deodorizers are in use . Dietary sources are negligible (Schaum et al, 2003), and chlorobenzenes generally are not detected in drinking water or groundwater in the United States (USGS, 2006), but may be detected where industrial waste containing these chemicals has been discharged (IPCS, 2004). Chlorobenzenes volatilize from soil and water (ATSDR, 2007(ATSDR, , 2008.…”

PBT assessment and prioritization by PBT Index and consensus modeling: Comparison of screening results from structural models

“…Concern about these substances is based also on the potential large scale impact that PBTs can have in regard to geography and time, typically giving rise to serious human health and environmental effects over several generations. In fact, PBTs were found all over the globe in wildlife, food, human breast milk and blood (Schaum et al, 2003;LaKind et al, 2004;Thomas et al, 2006;Brown and Wania, 2008). Examples of typical and well known PBT substances are DDT, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins, various brominated flame-retardants, and several chlorinated pesticides.…”