Milk collection

Figures for the numbers of organic dairy cows in Europe (Foster Lampkin, 1999) indicated that in 1996 Great Britain still had only 3436 organic dairy cows, compared to Austria (87 068), Switzerland (32 504) and Denmark (21417). By 1999 Padel, et al. (2000) calculated that there were 45 million litres of organic milk produced in the UK. From 2000 to 2003 organic milk production in the UK increased by approximately 600%, and the total organic milk collected in 2003 was 293.4 million litres, of which 62% was sold as organic (Soil Association, 2003).

Trotter WJ. 1993. Pesticide residues in composited milk collected through the U. S. Pasteurized Milk Network. Journal of AOAC International 76(6) 1220-1225. 

Chlordecone was detected in 9 of 298 samples of human milk collected in the southern United States however, the detection limit was relatively high (1 pig/kg). Residues were detected only in women living in areas that had received mirex bait treatment for fire ant control (EPA 1978c). 

Breast milk During lactation human mammary tissue expresses the sodium iodide symporter [260], and thus significant transfer of perchlorate into human milk is likely. The presence of micrograms per liter concentrations of perchlorate in milk collected fi om US women [233] confirms lactation as a relevant perchlorate excretion path. If lactating women are secreting perchlorate in milk, then urine-based estimates of total perchlorate exposure for these individuals are likely to be lower than actual [242]. 

Dichlorobenzene (all isomers) was identified in 100% of 42 samples of human breast milk collected in 5 urban areas of the United States at concentrations of 0.04-68 ppb (Erickson et al. 1980). Dichlorobenzene (all isomers) was identified in human breast milk in 8 of 12 women who were residents of Bayonne, New Jersey (6 women), Jersey City, New Jersey (2 women), Bridgeville, Pennsylvania (2 women), and Baton Rouge, Louisiana (2 women) however, concentrations were not specifred (Pellizzari et al. 1982). 

Oxacillin and cloxacillin are the most widely used isoxazolyl penicillins, the latter being particularly appropriate for treatment or prevention of bovine staphylococcal mastitis. Following intramammary treatment of a lactating cow with three successive infusions of 200 mg/48 h each of sodium cloxacillin, residues were present in milk (detection limit equal to 3 ppb) from the treated quarter for 60 h after the last infusion crossover from treated to untreated quarter was also observed (59). When cloxacillin benzathine was administered by the intramammary route to dairy cows in the dry period at a dosage of 500 mg/quarter, cloxacillin residues were present neither in serum ( 25 ppb) sampled after 5 days of drug administration nor in milk ( 5 ppb), including the milk collected... 

Residue depletion studies in lactating cows given a single oral dose of 100 mg thiophanate/kg bw showed mean thiophanate residue concentrations of 440, 320, and 140 ppb in tlie milk collected at 6 h, 20 h, and 30 h milkings, respectively (9). However, milk collected at 44 h and thereafter was not found to contain detectable (detection limit 50 ppb) residue concentrations. 

The somewhat delayed appearance of the highest level of the sulfone metabolite could be accounted for by its two-step oxidization process that required production of the fenbendazole sulfoxide as an intermediate substrate (14). This elimination profile indicated that the predominant metabolite in the milk collected by 36 h was the fenbendazole sulfoxide, whereas in the milk collected from... 

When cows were dosed singly with an oral suspension of radiolabeled clorsulon at 7 mg/kg bw, average milk residue levels decreased from 0.54 ppm at 0.9 days posttreatment to 0.004 ppm at 6.9 day is posttreatment, with a half-life of 0.81 days (71). The unchanged drug was identified as the major residue component in the milk collected by the 4 day postdosing, and accounted for... 

Residue depletion studies are very limited for metronidazole. After intrauterine treatment of cows with metronidazole at the recommended dosage, residues of metronidazole and its main metabolite hydroxymetronidazole could be detected in the milk collected at 2 and 6 h after dosing residues declined to below the limit of detection at 43 h postdosing. 

Temporal trends have been reported for PCN concentrations in Swedish human milk collected from 1972 to 1992 with concentrations declining nearly tenfold by 1992 from 3.1 ngg-1 lw in 1972 [162,163]. In general, PCN concentrations in human tissues appear to be decreasing following changes in production and use patterns. In breast milk of women from Los Angeles, USA, PCN concentrations ranged from 1.7 to 3 ngg 1 lw [156]. 

Specific aspects of dairy production are covered by the model proposed by Wouda et al. (2002). While the model is relatively simple with respect to its mathematical structure (single-period, domestic setting, two production levels), it contains aspects such as milk collection from production regions, divergent material flows occurring in the first stage of dairy processing and transshipment of the respective intermediates between plants. 

Wong, C.K.C., Leung, K.M., et al., 2002. Organochlorine hydrocarbons in human breast milk collected in Hong Kong and Guangzhou. Arch. Environ. Contam. Toxicol. 43, 364-372. 

Kunisue, T., Someya, M., Kayama, F., Jin, Y.H., Tanabe, S., 2004. Persistent organochlo-rines in human breast milk collected from primiparae in Dalian and Shenyang, China. Environ. Pollut. 131, 381-392. 

In addition to the studies on the trends of POP levels in the environmental samples, time trends of human exposure is also an important issue for understanding the long-term toxic impacts on general population. Minh et al. (2004) assessed the decline in the rate of human exposure to DDTs and PCBs over the 10 years period (1989 and 2001). A first-order kinetic approach was used to estimate the declining rate of DDTs and PCBs in human breast milk collected from Vietnam. The decrease in the POPs such as DDTs, PCBs, and HCHs in human breast milk was suggested to follow first-order kinetic (Noren Meironyte, 2000). Another important factor for the assessment is the half-life (Aieci, 2) defined as the duration in which initial concentrations decrease to a half. On the basis of the residue concentrations of OCs in 1989 reported by Schecter et al. (1989a) and the levels in 2001 obtained by Minh et al. (2004), the rate constant and tdeci/2 were estimated. 

Figure 18.16. Concentrations of DDTs in human breast milk collected from general public in Asian countries. References cited are similar to those in Fig. 18.15.

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