Plasticizers and BPA in spices and aromatic herbs of Mediterranean areas

Abstract This research is carried out in order to characterize the actual contamination by two ubiquitous environmental pollutants, plasticizers and Bisphenol A, in spices (black pepper, caraway and coriander) and aromatic herbs (fennel, laurel, mint, oregano, rosemary, thyme and verbena) from Algeria (n = 26), Tunisia (n = 65) and Italy (n = 53). Algerian samples seem to contain fewer residues than Italian and Tunisian samples. Among the Italian samples, only aromatic herbs, precisely mint, oregano, and laurel, were contaminated. In general, all Tunisian samples showed five plasticizers residues: the caraway, among the spices, and the rosemary, among the aromatic herbs, are found to contain more residues. Also, dietary intake of these contaminants by spices and aromatic herbs under analysis seems not to constitute a risk to the consumers. Graphical Abstract


Introduction
Aromatic herbs and spices of various types have been used, since the ancient times, as additives in culinary, medicinal, cosmetic and other compositions (Schweiggert et al. 2007). They play an important rule in the economy of the producing, importing and exporting countries. In particular, Mediterranean countries are the major producers of some spices (Doghein et al. 2004).
Similar to other agricultural products, spices and herbs may be subjected to chemical contaminations due to agricultural practices, soil treatment, cultivation in contaminated soil, presence of moulds possibly producing toxin secondary metabolites, and environmental contamination (Rozentale et al. 2018;Di Bella et al. 2017, 2019Santini et al. 2009;Mikusova et al. 2010;Haddaoui et al. 2016;Cammilleri et al. 2018;Cicero et al. 2017;Tripathy et al. 2015). Several researches about their beneficial effects for human health, linked to their antioxidative activity, can be found in literature, whereas about plasticizer and BPA (bisphenol A, 2,2-bis-(4-hydroxyphenyl propane) residues only a limited number of studies are available (Moreira et al. 2015;Di Bella et al. 2018). Today, the migration from plastic packing are considered as among the major sources of human exposure to these contaminants (Beltifa et al. 2017;Di Bella et al. 2014;Dugo et al. 2011;Lo Turco et al. 2015;Lo Turco et al. 2016), which however could also resulted from pollutants of the marine and terrestrial environment and/or agriculture practice (Cao et al. 2015;Larsson et al. 2017;Szczepa nska et al. 2018).
In particular, soils can be contaminated with plasticizers by atmospheric precipitations, water irrigation, fertilizer and biosolid applications Mo et al. 2008;Zhang et al. 2012).
Also the monomer BPA, used primarily to produce epoxy resins and polycarbonate plastics (Kang et al. 2006;Teuten et al. 2009), is ubiquitous in the environment (Fu and Kawamura 2010). BPA pollution in soil can be correlated with human activities, including also human wastes, domestic and/or industrial (Kang et al. 2006;Kawahata et al. 2004).
Both contaminants, plasticizers and BPA, can threaten human health. Some plasticizers are included in the list of toxic chemical by the EPA (Environmental Protection Agency) since they can contribute to the insurgence cancer, allergies, endocrine disorders, alterations in the reproductive system (Crinnion 2010;Castillo and Barcelo 1997) and might persist in human body tissues for longer periods (Peñalver et al. 2000). BPA, which shows moderate estrogenic activity, has a potential to distrupt thyroid hormone action and an influence on reproduction (Vom Saal and Hughes 2005; Ghisari and Bonefeld-Jorgensen 2009).
The opinion that plasticizers and BPA are ubiquitous environmental pollutants had led us to evaluate the residues of 18 plasticizers and BPA in 144 Algerian, Tunisian and Italian samples of herbs and spices to characterize the actual contamination status and to study the daily dietary intake of these contaminants based on herbs and spices consumption.

Results and discussion
In all analyzed samples, DMP, DiBA, DBA, DPrP, BB, DPhP and BPA residues were lower than their LOQ. As seen in Figure 1, Algerian samples seem to contain fewer residues then Italian and Tunisian samples, precisely only DMA, DBP, DcHeP were found at concentration 0.40 mgÁg À1 whereas DEHS is always 1.23 mgÁg À1 . Among the Italian samples, only aromatic herbs, precisely mint, oregano, and laurel, were contaminated by DMA, DEP, DiBP, DBP, DEHP, DEHT and DEHS. In particular, residues higher than 1 mgÁg À1 were detected only in mint (DiBP) and in oregano (DEHS). In general, all Tunisian samples showed at last five plasticizers residues: the caraway, among the spices, and the rosemary, among the aromatic herbs, are found to contain more residues. DEHP and DEHT were found in all types of samples at concentration next to 1 mgÁg À1 ; also DMA was always found but constantly lower than 0.5 mgÁg À1 . DEHS was detected only in caraway, coriander, oregano e rosemary but with values higher than others. All other phthalates and adipates were rarely detected.  In order to assess any risks to humans, it is essential to take into account the quantity of herbs and spices consumed habitually.
As reported on FAOSTAT (2013), intakes of spices/herbs amounted to 0.78, 1.13 and 1.66 g/capite/day in Europe, USA and Nord Africa, respectively. Figures 2 and 3 show the EDI values and hazard index (HI) values.
The intake of plasticizers was obtained considering an adult weighing 60 kg and a 100% gastrointestinal uptake as: {1x plasticizer amount in a different daily intake (lg) (FAOSTAT 2013) x1}/bw. HI values were calculated as HI ¼ EDI/TDI, for DEP, DBP, DEHA, DEHP and DiNP. Based on the results obtained, no hazardous quantities of these contaminants are assumed through feeding.

Experimental
See Supplementary materials for: chemicals, samples, instrumentation, and GC-MS method validation.

Conclusions
The results obtained in this research show a different concentration of plasticizers and BPA in spices and aromatic herbs. Probably in Algeria, Tunisia and Italy there are different environmental pollutions and/or agricultural practices. In any case, even assuming a high daily spice and herb consumption as in North Africa, the results suggested that intake of these contaminants by spices and aromatic herbs under analysis seems not to constitute a risk to the consumers.

Disclosure statement
No potential conflict of interest was reported by the authors.