Table 1.

Summary of studies reporting associations between exposure to environmental chemicals and endpoints relevant to T1DM development (T1DM, T2DM or beta-cell/immunomodulations). A “+” sign in front of the reference indicates positive association between chemical exposure and the respective endpoint (diabetes or beta-cell/immune modulations), while a “−” sign indicates no association between chemical exposure and T1DM or having inverse associations. “(+)” in front of the reference indicates that the exposure was measured in common drinking water, not for the individual, resulting in more uncertain conclusions.

Subgroup of chemicals	Environmental chemical	TIDM epidemiology	TIDM animal studies	T2DM epidemiology	Beta-cell modulations	Immuno modulations	Likelihood for T1DM influence
Polychlorinated biphenyls	PCB	+ Longnecker et al. 2001 [16]		+ Everett et al. 2011 [22]		+ Schmidt and Bradfield 1996 [23]	+++ (−)
		+ Langer et al. 2002 [18]		+ Carpenter 2006 [21]
		− Rignell-Hydbom et al. 2010 [17]
Dioxins	TCDD/dioxin		− Shinomiya et al. 2000 [28]	+ Cranmer et al. 2000 [39]	+ Martino et al. 2013 [25]	− Rohlman et al. 2012 [30]	++ (−)
			− Kerkvliet et al. 2009 [29]	+ Pelclová et al. 2006 [40]	+ Kurita et al. 2009 [26]	− Li and McMurray 2009 [33] − Schulz et al. 2012a, b [34, 35]
				− Warner et al. 2013 [41]	+ Kim et al. 2009 [27]	− Hanieh 2014 [32]
						+ Ishimaru et al. 2009 [36]
						+ Mustafa et al. 2011a, b [37, 38]
Organochlorides (pesticides)	DDT/DDE	− Rignell-Hydbom et al. 2010 [17]		+ Codru et al. 2007 [43]		+ Yang et al. 2012 [44]	++ (−)
				+ Philibert et al. 2009 [45]		− Li and McMurray 2009 [33]
				+ Taylor et al. 2013 [46]
				+ Turyk et al. 2009 [47]
Polybrominated biphenyls (Flame retardants)	PDBE			+ Lee et al. 2011 [48]	+ Zhang et al. 2013 [49]	+ Hennigar et al. 2012 [50]	++
				− Turyk et al. 2009 [47]		+ Turyk et al. 2008 [51]
				+ Llm et al. 2008 [52]
Perfluorinated alkyl substances	PFAS			+ Lind et al. 2014 [53]	+ Lin et al. 2009 [54]	+ Grandjean et al. 2012 [55]	++
					+ Lv et al. 2013 [56]	+ Granum et al. 2013 [57]
						+ Borg et al. 2013 [58]
Endocrine disruptors	BPA		+ Bodin et al. 2013 [59]; Bodin et al. 2014 [60]	+ Aekplakorn et al. 2014 [61]	+ Song et al. 2012 [62]	+ Bodin et al. 2014 [60]	++++
				+ Ahmadkhaniha et al. 2014 [63]	+ Soriano et al. 2012 [64]
				− Kim and Park 2013 [65]	+ Nadal et al. 2009 [66]
				+ Sabanayagam et al. 2013 [67]
				+ Shankar and Teppala 2011 [68]
				+ Silver et al. 2011 [69]
				+ Sun et al. 2014 [70]
	Triclosan					+ Paul et al. 2009 [71]	+
						+ Zorrilla et al. 2009 [72]
						+ Koeppe et al. 2013 [73]
	Phthalates			+ Huang et al. 2014 [74]		+ Mankidy et al. 2013 [75]	+
				+ James-Todd et al. 2012 [76]		+ Vetrano et al. 2010 [77]
				+ Kim et al. 2013 [78]		+ Sarath Josh et al. 2014 [79]
				+ Lind et al. 2012 [80]
				+ Stahlhut et al. 2007 [81]
				+ Svensson et al. 2011 [82]
				+ Trasande et al. 2013 [83]
Metals	Arsenic			+ Rager et al. 2014 [84]	+ Douillet et al. 2013 [85]	+ Dangleben et al. 2013 [86]	++
				+ Tsai et al. 1999 [87]	+ Lu et al. 2011 [88]	+ Ahmed et al. 2012 [89]
				+ Bräuner et al. 2014 [90]	+ Yang et al. 2012 [44]	+ Banerjee et al. 2009 [91]
				+ Lee and Kim 2013 [92]		+ Lu et al. 2014 [93]
				+ Mahram et al. 2013 [94]
	Organotins				+ Miura et al. 1997 [95]; Miura et al. 2012 [96]		+
					+ Zuo et al. 2014 [97]
					− Matsui et al. 1984 [98]
Nitroso compounds	Nitrates and nitroso amines	+ Dahlquist et al. 1990 [99]			+ Helgason and Jonasson 1981 [100]		++ (+)
		+ Benson et al. 2010 [101]			+ Wilson et al. 1983 [102]
		− Samuelsson et al. 2011 [103]
		− Cherian et al. 2010 [104]
		(+) Kostraba et al. 1992 [105]
		(+) Parslow et al. 1997 [106]
		(+) van Maanen et al. 1999 [107]
		(+) Helgason 1991
	Streptozotocin		+ Szkudelski 2001 [108]		+ Schnedl et al. 1994 [109]		++
			+ Leiter 1982 [110]		+ Wang and Gleichmann 1998 [111]
			+ Rossini et al. 1977 [112]		+ Lenzen 2008 [11]
	Alloxan		+ Rerup 1970 [113]		+ Lenzen 2008 [11]		++
					+ Szkudelski 2001 [108]
					+ Eizirik et al. 1994 [114]
	Bafilomycin		+ Hettiarachchi et al. 2004 [115]		+ Myers et al. 2003 [116]		++
					+ Hettiarachchi et al. 2006 [117]
	Vacor				+ Myers et al. 2003 [116]		+
					+ Esposti et al. 1996 [118]
					+ Taniguchi et al. 1989 [119]
					+ Wilson and Gaines 1983 [120]
	Cereulides				+ Virtanen et al. 2008 [121]		+
					+ Vangoitsenhoven et al. 2014 [122]
Air pollution	Particulate matter			+ Eze et al. 2014 [123]		+ Danielsen et al. 2011 [124]	++
				+ Hathout et al. 2001 [125]		+ den Hartigh et al. 2010 [126]
				+ Brook et al. 2013 [127]		+ Yan et al. 2011 [128]
	Ozone	+ Hathout et al. 2006 [129]				+ Bass et al. 2013 [130]	+++
	Carbon monoxide			+ Janghorbani et al. 2014 [131]			+
				+ Dales et al. 2012 [132]
				− Nikolic et al. 2014 [133]
	Maternal/smoking	+ Hathout et al. 2006 [129]		+ Thiering et al. 2011 [134]	+ Rasouli et al. 2013 [135]		+++ (−)
		− Dahlquist and Kallen 1992 [136]		+ Persson et al. 2000 [137]
		− Hjern and Söderström 2008 [138]
		− Ievins et al. 2007 [139]
		− Johansson et al. 2008 [140]
		− Marshall et al. 2004 [141]
		− Rasouli et al. 2013 [135]
		− Robertson and Harrild 2010 [142]
	PAH			+ Zhao et al. 2014 [183]		+ Nadeau et al. 2010 [144]	++
	polycyclic aromatic hydrocarbon					+ den Hartigh et al. 2010 [126]
						+ Danielsen et al. 2011 [124]
						+ Perreault et al. 2013 [145]

⁺Beta-cell toxicity or immunomodulation.

⁺⁺Beta-cell toxicity and immunomodulation.

⁺⁺⁺Beta-cell toxicity or immunomodulation and T1DM human or animal study.

⁺⁺⁺⁺Beta-cell toxicity and immunomodulation and T1DM human or animal study.